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The global cotton industry is distinguished by its numerous industrial uses of the plume as well as by high production costs. Excessive vegetative growth can interfere negatively with productivity, and thus, applying growth regulators is essential for the development of the cotton culture. The objective of this study was to evaluate the development and yield of the cotton cultivar FMT 701 with the application of mepiquat chloride to seeds and leaves. The experimental design used a randomized block design with four replications, arranged in bands. The treatments consisted of mepiquat chloride rates (MC) (0, 4, 6, 8 and 10 g a.i. kg-1 of seeds) applied directly to the cotton seeds and MC management by foliar spray using a 250 mL ha-1 rates that was administered under the following conditions: divided into four applications (35, 45, 55 and 65 days after emergence); as a single application at 70 days; and without the application of the product. The mepiquat chloride applied to cotton seeds controls the initial plant height and stem diameter, while foliar application reduces the height of the plants. After application to seed, foliar spraying MC promotes increase mass of 20 bolls, however no direct influence amount bolls per plant and yield of cotton seed. Higher cotton seed yield was obtained with a rate of 3.4 g a.i. MC kg-1 seeds. [ABSTRACT FROM AUTHOR]

This study was carried out to determine the effects of different salinity levels in irrigation water for some cotton varieties under Diyarbakır Province of Southeastern Anatolia Region in 2007 using experiments utilizing lysimeter-like drainage type metal containers. Four different salinity levels (T0: 0.32 dS/m, T1: 5 dS/m, T2: 9 dS/m and T3: 13 dS/m) and 3 different cotton cultivars (P1: Berke, P2: Stonville-453 and P3: Teks) were utilized during the treatments. The least affected cultivar from the salinity was Berke. Compared to the cultivar of Berke, the seed-cotton yields of Stonville-453 and Teks were less than 8.3 % and 23.1 %, respectively. The values of salinity threshold for irrigation water according to the cotton cultivars were calculated as Ct=4.45 (Berke), Ct=4.32 (Stonville-453) and Ct=3.72 (Teks). The values of salinity threshold for soil were Ct=6.58 (Berke), Ct=7.46 (Stonville-453), Ct=6.84 (Teks). The results showed there is no significant loss on seed-cotton yield when irrigation water salinity of up to the value of 4.45 dS/m was used. [ABSTRACT FROM AUTHOR]

Regional variations in environmental conditions, cultivars, and management practices necessitate locally derived tools for crop water use estimation and irrigation scheduling. A study was conducted in northeast Louisiana (mid-south US) aimed at estimating daily crop evapotranspiration (ET c ) and reference evapotranspiration (ET o ) and thus, developing local crop coefficient ( K c ) curves for irrigated upland cotton. ET c was determined using paired weighing lysimeters installed near the middle of a 1-ha cotton field and planted with cotton as in the rest of the surrounding field, while ET o was calculated using the Standardized Reference Evapotranspiration Equation (SREE) developed by the American Society of Civil Engineers (ASCE), using estimates of weather variables from a nearby standard reference weather station. Stage-specific K c values averaged over 2 years were 0.42, 1.25 and 0.70 for initial, midseason, and end season stages of cotton, respectively. The initial-stage K c value was approximately 26% lower than the Food and Agricultural Organization (FAO)-adjusted initial K c value. The mid- and end-season K c values obtained in the study were approximately 6% and 11% greater, respectively, than the FAO-adjusted K c values for the corresponding stages. The observed differences among the local stage-specific K c values (especially at initial growth stage of cotton) and the FAO-adjusted initial K c values could be attributed to regional variations in environmental conditions, cultivars, and management practices. The ET c and K c values obtained from this study provide research-based information for future studies and the development of K c -based irrigation tools in this region. [ABSTRACT FROM AUTHOR]

High salinity in association with boron toxicity is becoming very adverse for crop production in arid to semi arid areas throughout the world. In order to investigate the effect of salinity in combination with boron toxicity on six cotton varieties, a hydroponic study was conducted in the rain protected wire house using 1/2 strength Hoagland's nutrient solution as a growth medium. One week after transplantation, different levels of salinity i.e. 70 and 140 mM were developed with NaCl. The concentration of boron (5 and 10 mM) was created using boric acid (H3BO3). The plants were harvested after four weeks of salinity and boron toxicity development. The result indicated that the chlorophyll contents in variety FH-114 were less affected against combined stress condition because it accmulated less Na+ and boron but acquired more K+ which result into batter growth as compared to other varieties whereas NIAB-846 was found very sensitive against combined stress. The trend regarding the varietal behaviour with salinity and boron stress was FH-114 NIAB-777 IUB-222 SG1-AA FH-113 NIAB-846 on the basis of this study; the variety FH-114 can be grown in slinity and boron stress conditions because it has potential to regulate growth by regulating Na+/K+ uptake. [ABSTRACT FROM AUTHOR]

Drought is one of the major abiotic stresses affecting crop plants worldwide including cotton. QTLs were identified to assess the genetic control of relative leaf water contents, excised leaf water loss, cell membrane stability, stomatal size and frequency under drought. An F[sub 2] population was developed by an intraspecific crossing between drought tolerant genotype (FH-207) and drought susceptible genotype (FH-901) of Gossypium hirsutum. A total of 2365 EST-SSR primers were screened to identify polymorphism between two contrasting parents. One hundred primers showing polymorphic amplification were used to score F[sub 2] population for QTL mapping. Two QTLs for relative leaf water contents on chromosome A5, one for excised leaf water loss on chromosome A7, one for cell membrane stability on chromosome A1, one for stomatal size on chromosome A6 and one for stomatal frequency on chromosome A13 were identified. These QTLs would be helpful to develop drought tolerant cotton cultivar. [ABSTRACT FROM AUTHOR]

Yield and fibre quality performance of DNH-105 strain in comparison with standard cotton varieties (CIM-573, CRIS-342, Gomal-93, NIAB-112 and CIM-612) was assessed at Cotton Research Station, D.I. Khan, Pakistan, during growth season 2011-2013 in a randomized complete block design replicated thrice. The strain DNH-105 gave optimum yield owing to more bolls per plant (37.2), boll weight (3.4 g) plus higher ginning out turn (39.9%) compared to the standard varieties of cotton in Pakistan. The quality characteristics such as fibre length (29.2 mm), strength (28.5 g tex-1), micronaire (4.3μg inch-1) and uniformity (80.2%) were also higher for DNH-105 than other varieties. Ginning out turn ranged from 37.2 (CIM-612) to 39.9% (DNH-105). Fibre length ranged from a low of 28.3 (CIM-612) to a high of 29.2 mm (DNH-105) while fibre strength was observed 25.0 (CIM-612) to 28.5 (DNH-105) g tex-1. Micronaire value ranged from 4.3 (DNH- 105) to 4.8 μg inch-1 (CIM-612). Fibre uniformity ranged from a low of 77.1 (CIM-612) to a high of 80.2% (DNH-105). It is concluded that strain DNH-105 has high yield potential and best suited to ago-climatic conditions of Dera Ismail Khan, Pakistan as compared to the other varieties of cotton. [ABSTRACT FROM AUTHOR]

Ten Gossypium hirsutum lines tolerant to jassids were selected as donors along with three standard varieties viz., MCU 5, MCU 7, MCU 12 for crossing programme. This study indicated the predominance of non additive gene effects for all the yield and yield contributing characters which signifies the scope for exploitation of heterosis. Among the lines, DHY 286, Badnawar 1 and SVPR 2 were found to be good general combiners for single plant yield. Among the jassid resistant parents, DHY 286 was found to possess more favourable genes for number of bolls per plant, boll weight, single plant yield and seed index. The highly resistant parent KC 2 was observed as good general combiner for bolls per plant and this parent can be used in breeding programme for improving yield coupled with resistance. The tester MCU 5 is a good general combiner for yield contributing traits. By hybridizing the resistant genotypes with MCU 5, favourable gene combinations could be accomplished for the yield and yield contributing characters. The hybrids showing high per se performance for yield, DHY 286 x MCU 5, Badnawar 1 x MCU 5, Badnawar 1 x MCU 7 and Badnawar 1 x MCU 12 also showed resistance to jassids and deserve further exploitation. [ABSTRACT FROM AUTHOR]

Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4–5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B1 + B2 (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake. [ABSTRACT FROM AUTHOR]

Development of versatile hybrids has been one of the leading objectives of Plant breeders. Difficulties have been observed in the development of F1 Cotton hybrids thereby triggering the possible utilization of F2 hybrids for commercial cultivation. An experiment was conducted to determine the heterotic behavior of F1 and F2 hybrids. Twelve lines were crossed with four testers for development of 48 hybrids followed by selfing for the generation of F2 hybrids. Z33 × IUB09 and CIM473 × IUB08 were outstanding F1 hybrids while Z33 × IUB09 and CRSM2007 × IUB09 were superior hybrid combinations in F2. Both F1 and F2 hybrids performed extraordinarily well for all of the traits studied in present experiment and incurred mild inbreeding depression in F2 population. In addition to the F1 and F2 population analysis, selected elite hybrids performed significantly higher than three commercial varieties and among them Z33× IUB09 was top yielder followed by CRSM2007 × IUB09 and CIM496 × IUB09. Superior hybrids manifested the predominant influence of non-additive gene action other than dominance coupled with best hormonal combinations. It is inferred that Z33 × IUB09 performed well not only in F1 and F2 populations but in field comparison as well. Such hybrids must be extracted by breeding efforts and could be launched for commercial cultivation. [ABSTRACT FROM AUTHOR]

Seedlings of 50 varieties/lines of Gossypium hirsutum were screened for water stress tolerance during 2010-2013. Indices of water stress tolerance were calculated on the basis of shoot and root lengths. Based on similarities and differences, CIM-496, 149F, DPL-26, BOU-1724 and B-557 were found tolerant to moisture stress, whilst FH-1000, NF-801-2-37, MNH-129 and H-499 exhibited susceptibility to water stress. Results of screening revealed that variability among germplasm was present which may be exploited through hybridization. Therefore, F1 crosses were developed in the field keeping stress tolerant genotypes as lines and susceptible as testers using line × tester technique. The genetic material developed was field-planted and 50% moisture stress was applied to examine responses in plant height and seed cotton yield. The analysis of F1 and parental data revealed the preponderance of non-additive genetic effects for both traits. Testers and interaction between parents contributed more to expression of plant height and seed cotton yield respectively. CIM-496 with significant and positive general combining ability estimates, i.e. 1.83 for plant height and 3.65 for seed cotton yield was found to be good general combiner for both the traits. The cross B-557 × H-499 was the best varietal combination for plant height and seed cotton yield. Non-additive variation for both traits suggests possibility of using this material for hybrid development in drought hit areas. Plant height did not significantly affect seed cotton yield as shown by non-significant correlation coefficient (0.3). [ABSTRACT FROM AUTHOR]

Genotype × environment interaction (G × E) plays a fundamental role in important agricultural traits such as grain yield or disease resistance. Therefore, modeling G × E is essential for the selection of high yielding and well-adapted varieties. The availability of new sources of genetic and environmental information (e.g., dense panels for molecular markers coupled with large numbers of environmental covariates [EC]) provides important opportunities for studying and exploiting G × E. However, incorporating highdimensional genetic and environmental data and accounting for potential interactions is not an easy task. Recently we developed a genomic model that incorporates molecular markers, EC, and the interactions between them using covariance functions. In this paper we demonstrate how the same approach can be applied in cases where genetic information is based on pedigrees instead of molecular markers. We evaluated the models using a collection of 7809 grain yield records obtained from 582 cotton lines evaluated in 2 yr (2011 and 2012) over nine locations. A total of 76 EC were available and used to model main and interaction effects. Estimates of variance components indicated that G × E explained a sizable proportion of the phenotypic variance, and two cross-validation analyses indicated that modeling G × E increases prediction accuracy by a considerable margin. To the best of our knowledge, this is the first study considering both pedigree and EC for the analysis of cotton yield. The models described here can be used for prediction of genetic merit and for selection for target environments. [ABSTRACT FROM AUTHOR]

Potassium (K) deficiency and salinity are major environmental stresses affecting the growth and agricultural production of cotton ( Gossypium hirsutum) plants worldwide. In an effort to improve potassium uptake and tolerance to salt stress through genetic engineering, we inserted AlHAK1 into cotton via Agrobacterium-mediated transformation, and then transgenic lines were obtained. To test their response to K-starvation and salt stress, we cultured seedlings from the wild type (WT) and three homozygous overexpression lines (T generation) in plastic pots and treated them with a modified half-strength Hoagland's solution supplemented with different concentrations of potassium or sodium: NT (normal treatment with standard amounts of K and Na), KT (additional 0.05 mM KCl), ST (additional 150 mM NaCl), or KST (0.05 mM KCl plus 150 mM NaCl). After 15 days, all transgenic lines exhibited significantly larger values for shoot and root lengths and biomass (shoot dry weight or root dry weight) when compared with WT plants. Most root morphological parameters for the transgenics were also increased, e.g., total lengths, specific root lengths and surface areas. However, average root diameters were significantly lower than that of the WT ( P < 0.05 or P < 0.01). Under salt-stress conditions, the ratios for K/Na were higher in the leaves and roots of transgenic plants, and they also had less malondialdehyde and hydrogen peroxide (HO) than the WT tissues. Those responses paralleled greater activities by the antioxidant enzymes superoxide dismutase and peroxidase. We clearly demonstrated that cotton plants transformed with a high-affinity K transporter gene have enhanced K uptake and salt tolerance. These findings could serve as a promising step toward the development of new cotton cultivars with improved potassium uptake and tolerance to salt stress, and they have significant implications for increasing crop yields on high-salinity soils where potassium levels are low. [ABSTRACT FROM AUTHOR]

Developing and deploying cotton cultivars with high nutrient uptake, use efficiency and tolerance to nutrient related soil stresses is desirable to assist sustainable soil management. Genetic variation, heritability, selection response and quantitative trait loci (QTLs) were investigated for five macronutrients (P, K, Ca, Mg, S) and five micronutrients (Fe, Mn, B, Zn, and Cu) in a recombinant inbred line (RIL) population from an inter-specific cross between Gossypium hirsutum cv. Guazuncho 2, and G. barbadense accession VH8-4602. Na and K/Na ratio were also studied as the imbalance between Na and other nutrients is detrimental to cotton growth and development. The concentrations of nutrients were measured for different plant parts of the two parents and for leaf samples of the whole population collected at early to peak flowering in field experiments over two years in a sodic Vertosol soil. Parental contrast was large for most nutrient concentrations in leaves when compared with other plant parts. Segregation for leaf nutrient concentration was observed within the population with transgression for P, K, K/Na ratio and all micronutrients. Genotypic difference was the major factor behind within-population variation for most nutrients, while narrow sense heritability was moderate (0.27 for Mn and Cu, and 0.43 for B). At least one significant QTL was identified for each nutrient except K and more than half of those QTLs were clustered on chromosomes 14, 18 and 22. Selection response was predicted to be low for P and all micronutrients except B, high for K, Na and B, and very high for K/Na ratio. Correlations were more common between macronutrients, Na and K/Na ratio where the nature and strength of the relations varied (r=-0.69 to 0.76). We conclude that there is sufficient genetic diversity between these two tetraploid cotton species that could be exploited to improve cotton nutrient status by introgressing species-unique favourable alleles. [ABSTRACT FROM AUTHOR]

To compare the effect of planting time and N levels on phenology and seed cotton yield of Bt and non -Bt cotton, an experiment was laid out at Students' Farm, University of Agriculture, Faisalabad, Pakistan. Two cotton cultivars; FH-113 (Bt) and CIM-496 (non-Bt) were planted during mid March and mid May using 115, 145 and 175 kg ha-1 N levels. Planting times were placed in main plots, varieties in sub plots and N levels in sub sub plots in randomized complete block design with three replications. All the interactions (sowing date × varieties, sowing dates × nitrogen levels, varieties × nitrogen levels, sowing dates × varieties × nit rogen levels) were non significant for parameters (Days taken to squaring, flowering, first boll splition, vertical and horizontal flower interval, boll maturation period, node above white flower, node number for first fruiting branch, first fruiting branch height, earliness index, number of monopodial and sympodial branches per plant, average boll weight per plant, seed cotton yield kg ha-1) under discussion except variety × sowing date for seed cotton yield. Mean values for various phenological events like days taken to squaring, first flower and first boll splition, BMP (boll maturation period), first fruiting branch height (cm), first fruiting branch node number and node above white flower varied invariably between Bt and non Bt sown at different times. Vertical as well as horizontal flower intervals remained unaffected. Maximum seed cotton yield was recorded in FH-113 at mid March planting and minimum in CIM-496 at mid May planting. A N level of 145 kg ha-1 gave maximum seed cotton yield against the minimum with 115 kg ha-1. It was concluded that performance of Bt cotton was better in both mid March and mid May planting with respect to seed cotton yield per hectare. [ABSTRACT FROM AUTHOR]

Phytochemical and antioxidant composition of crude extracts, obtained from various parts of desert cotton (Aerva javanica) using three solvents of varying polarity such as hexane, methanol and water, was determined. Phytochemical screening confirmed the presence of flavonoids, cardiac glycosides, saponins, tannins and ascorbic acid in each part. Total extractable components, total phenolic compounds, total tannins and total flavonoids of different extracts ranged from 3.1±0.60 to 31.89±1.76, 0.11±0.01 to 3.54±0.36, 0.041±0.001 to 2.02±0.150 and 0.016±0.001 to 0.93±0.08 g/100g dry weight respectively. Trolox equivalent total antioxidant content, Iron reducing capacity and lenoleic acid reduction capacity ranged from 0.14±0.007 to 3.43±0.44 g/100g dry weight, 0.11±0.004 to 0.61±0.16 (Absorbance at λ=700nm) and 25.5±3.1 to 52.45±3.87% respectively. DPPH (2, 2-diphenyl-1- picrylhydrazyl), ABTS [2, 2-azino-bis (3-ethylebenzothiazoline-6-sulfonic acid] and hydroxyl radical scavenging activities ranged from 22.89±0.66 to 78.16±0.43, 37.48±0.32 to 91.5±0.18 and 13.45±0.64 to 52.6±2.1% respectively. Statistically significant difference in phytochemicals and antioxidant properties was observed among the extracts of varying polarity. Water extract of leaves and stem was found to be comparatively rich in phytochemicals and antioxidants which suggest the preferable use of polar solvents for extraction of such substances from plant material. The results would be a significant contribution regarding phytochemical and antioxidant importance of desert cotton. [ABSTRACT FROM AUTHOR]

Cotton Gosspium hirsu' tum L. is most important cash crop of Pakistan and important trade commodity of the world because of its exportability as well necessary domestic use. The cotton growers have to combat with an insect pest complex using different IPM techniques for successful cotton production. This fight was facilitated when the Lepidopterous pests ie. bollworms of cotton were managed by use of transgenic resistant varieties commonly known as Bt varieties/cultivars which have been registered for general sowing or which are commonly available to some farmers for· sowing at his field. Use of these transgenic Bt cultivars has been so popular in farming community that area under these has rigorously increased, starting from nearly last 10 years, now Bt varieties have almost replaced the conventional non-Bt varieties (survey of >2000 farmers in district Lodhran). Bt cultivars worked satisfactorily for last many years except some limited and short duration problems of bollworms reported from different pockets, that were usually because of mixed seed. In last cotton season 2014, the infestation of pink bollworm Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae) intensified tremendously and it was reported from almost all the cotton growing tract of Punjab. Owing to these reports studies were carried out in 3 subdivisions of Lodhran from 10 different Bt-varieties of cotton sown in that subdivision. 50 bolls were plucked from all the fields at random in· the month of October, 2014. In total 1549 collected bolls were kept in paper bags for a week and then percentage of damaged bolls as well as number of live larvae were recorded from all samples. The results were alarming to note all of 17 cultivars collected for study were susceptible showing 24.49 % to 100 % infestation. The average intensity of alive larvae per boll was 109.6 % inside the infesteQ boll. The situation spells a serious threat and dem~nds the immediate attention of cotton growers, ' breeders, biotechnologists, seed prooucers, extension workers, entomologists and research workers. [ABSTRACT FROM AUTHOR]

This study was carried out in Söke district of Aydin province in 2012-2013 in order to determine population changes of some significant cotton pests and natural enemies in the cotton planted as a second crop (Gossypium hirsutum L.) varieties. In the study, May 373, Gloria and Flash cotton seeds were commonly used. At the end of the study, in 2012, Bemisia tabaci, Frankliniella spp. and Liriomyza trifolii were detected in maximum density and regarded as significant statistically while Aphis gossypii, Tetranychus spp. and Frankliniella spp. were reached to the maximum density in May 373 and regarded as significant statistically in 2013 and followed by Gloria and Flash varieties. As for natural enemy densities, the highest natural enemy density, the individuals belonging to the order Coleoptera and Heteroptera were observed in May 373 and Flash at most, Gloria followed them. In the order Neuroptera, the difference was not observed statistically among ranges in terms of density. At the end of the study, no difference was found in fiber fineness, fiber length, uniformity and elasticity in both years in terms of highest yield rate while resistance was regarded as significant and the feature of the most resistant fiber was in Gloria in both years, no difference was found among May 373 and Flash. As a conclusion, it became evident that more hairs used might be used within integrated pest control in fighting with pests. [ABSTRACT FROM AUTHOR]

One option available to cotton (Gosspyium hirsutum L.) producers for control of glyphosate [N-(phosphonomethyl)glycine]-resistant (GR) weeds is the use of glufosinate [(2RS)-2-amino-4- [hydroxy(methyl)phosphinoyl]butyric acid] (Liberty 280SL, 24.5% [w/v] glufosinate-ammonium salt) in glufosinate-tolerant, transgenic cotton cultivars. A field experiment conducted in 2011 and 2012 in Florence, SC, examined the effects of glufosinate on the growth, lint yield, and fiber quality of WideStrike and Liberty-Link cotton cultivars. Five WideStrike cultivars and three Liberty-Link cultivars were sprayed topically at the 1- to 3-leaf stage and the 7- to 9-leaf stage with glufosinate at 0.59 kg ha-1. Glufosinate- and weed-free plots were maintained as controls for each cultivar. Reduced plant health and increased leaf injury were observed in both Liberty-Link and WideStrike cultivars following glufosinate applications, but sprayed WideStrike cultivars displayed as much as 11% greater leaf injury than sprayed Liberty- Link cultivars. No differences in lint yield were found between sprayed WideStrike or Liberty-Link cultivars and their respective controls. However, averaged across all cultivars, lint yield of cotton sprayed with glufosinate was 105 kg ha-1 greater than unsprayed cotton. Yield increases of sprayed cotton appeared to be related to increased boll production at the first fruiting position and between nodes 11 and 15. Glufosinate had no effect on any fiber property evaluated. Cotton producers planting WideStrike or Liberty-Link cotton cultivars and using glufosinate at labeled rates can adequately control GR weeds without negatively affecting lint yield or fiber quality. Cotton producers may also possibly experience slight lint yield increases as a result of glufosinate application in WideStrike and Liberty-Link cotton cultivars. [ABSTRACT FROM AUTHOR]

Abstract One of the objectives of this study was to estimate gene action and the type of inheritance of investigated traits in cotton. Another objective was to evaluate general combining ability of parents and special combining ability of F1 diallel crosses and to select the superior F1s that can be used in future breeding programs of cotton. Additive and dominant components were found significant for investigated traits. Number of bolls and lint percentages were effective in the control of additive type of gene action with partial dominance, but seed-cotton yield was also effective in the control of additive type of gene action with over-dominance. Greater parents were 'Paum-15' and 'Stoneville- 453' for the number of bolls and the seed-cotton yield; 'Stoneville-453' and 'Nazilli-84S' for the lint percentage. Greater cross combinations were 'Paum-15' x 'Stoneville-453'; 'Stoneville-453' x 'Nazilli-84S'; 'Stoneville-453' x 'Fantom'; 'Stoneville-453' x 'Delcerro' and 'Stoneville- 453' x 'Giza-45' diallel crosses for the number of bolls; 'Paum-15' x 'Nazilli-84S', 'Stoneville-453' x 'Fantom', 'Nazilli-84S' x 'Delcerro' and 'Nazilli-84S' x 'Giza-45' diallel cross for the lint percentage, 'Paum-15' x 'Stoneville-453', 'Paum-15' x 'Nazilli-84S', 'Stoneville-453' x 'Nazilli- 84S', 'Stoneville-453' x 'Fantom', 'Stoneville-453' x 'Delcerro', 'Stoneville-453' x 'Giza-45', 'Nazilli-84S' x 'Fantom' and 'Nazilli-84S' x 'Delcerro' diallel crosses for the seed-cotton yield. [ABSTRACT FROM AUTHOR]

Wheat–cotton double cropping is the leading cropping system in the Yellow River Valley and the Yangtze River Valley in China. To comprehend the effects of cropping systems on the radiation use efficiency (RUE) in wheat–cotton double cropping, field experiments involved four cropping systems, namely monoculture cotton (MC), wheat/intercropped cotton (W/IC), wheat/transplanted cotton (W/TC) and wheat/direct-seeded cotton (W/DC) and two cotton cultivars were conducted in 2011/2012 and 2012/2013. The results showed that wheat–cotton double cropping improved radiation use by increasing the intercepted photosynthetically active radiation and RUE compared with monoculture cotton. Averaged over two years, the RUE of monoculture cotton was 1.20 g DM MJ −1 for Siza 3 and 1.14 g DM MJ −1 for CCRI 50, while that of double cropped cotton was 1.19–1.93 g DM MJ −1 higher than monoculture cotton, with the RUE of cotton in W/DC was the highest, followed by in W/TC and W/IC. The analysis of cropping systems effects on cotton canopy structure and light distribution indicated that the high RUE was associated with the favorable intra-canopy light distribution. Cotton in W/IC, W/TC and W/DC system intercepted 87.1%, 54.6% and 44.3% as much PAR as the monoculture cotton for Siza 3 and 86.9%, 59.3% and 46.2% as much PAR as the monoculture cotton for CCRI 50, respectively. Double cropping cotton intercepted significantly lower PAR than monoculture cotton, which is the result of the lower f PAR caused by initiation shading for IC, later planting for TC and delayed sowing for DC, respectively. Our results suggest that the key factor that limits cotton production in double cropping systems is their lower PAR interception rather than the RUE. Suggestions for further increasing the productivity of radiation should be based on improved capture of radiation by cotton in wheat–cotton double cropping systems. The early maturity cultivar might be more appropriate to double cropping sequential systems. [ABSTRACT FROM AUTHOR]

Heat stress is among one of the limiting and ever looming threats to cotton productivity in Pakistan. This factor inflicted huge losses in the recent years. In Pakistan genotypes developed for general cultivation face very high temperature of about 50 °C during the month of June which is about 20 °C more than the optimum temperature thus retard yield to greater extent. The plant parts like buds, flowers, fiber quality traits are greatly influenced due to high temperature. This mini review partially covers effect of heat stress on cotton fiber quality, plant parts, screening procedures, genetics and biotechnological aspects related to heat stress. All the information provided in the manuscript will help to better understand the phenomena of heat stress tolerance thus will ultimately aid in the development of heat tolerant cultivars in Pakistan. [ABSTRACT FROM AUTHOR]

To prove the effects of the protein content of cotton on development of A. lucorum nymph, 3 organs (leaf, square and flower) of different cotton varieties (Sumian9, Zhongmian29 and Lumian15) were adopted to feed Nymph of Apolygus lucorum respectively. Growth parameters of nymph and the protein content of 3 organs of different cotton varieties were measured. Two factors analysis of variance (Organ X Variety) to protein content, duration and survival rate of nymph were analyzed. Furthermore, the relationship between protein content of cot ton and nymph duration, survival rate were analyzed. The results showed that there was a highly significant difference in the protein content of different varieties, and the protein content of leaf or square was more than 14. 9 percent higher than that of flower in same cotton variety. There was a close correlation between feeding organs and survival rate, developmental duration of A. lucorum nymph on different cotton varieties. The correlation index was 0. 9976, 0. 9586, 0. 9377 between the protein content on the same organ of different cotton varieties and the developmental duration of nymph, respectively. The trends of survival rate feeding on the same organ of different cotton varieties were consistent. There was a good correlation between protein content of cotton and developmental duration, survival rate of nymph. [ABSTRACT FROM AUTHOR]

Cotton productivity is affected by water deficit, and little is known about the molecular basis of drought tolerance in cotton. In this study, microarray analysis was conducted to identify drought-responsive genes in the third topmost leaves of the field-grown drought-tolerant cotton ( Gossypium hirsutum L.) cultivar Acala 1517-99 under drought stress conditions. Water stress was imposed by withholding irrigation for 9 days in the early squaring stage, which resulted in 10-15 % reduction in plant growth compared to the well-watered plants. A total of 110 drought-responsive genes (0.5 % of the total genes) were identified, 79 % (88 genes) of which were drought-repressed and 21 % (22 genes) were drought-induced. The drought-induced genes were grouped into six functional categories including stress-related (ten genes, nine of which encode heat shock proteins), metabolism (three genes) and one gene each for transcription factor, proline biosynthesis and cellular transport. The drought-repressed genes were classified into 14 functional categories, comprising metabolism (20 genes), cellular transport (12 genes), stress-related (12 genes), regulation of gene expression (nine genes), transcription factor (four genes), signal transduction (seven genes) and two genes each for biosynthesis of secondary compounds, cell wall, fatty acids/lipids and chlorophyll, and protein degradation. Most of the genes have been reported in other plants as drought-tolerant/responsive. The responsiveness of 19 selected drought-responsive genes was validated by quantitative RT-PCR. Furthermore, primers were developed and assayed for all the drought-responsive genes to develop single-strand conformation polymorphic markers, many of which were found to be correlated with drought tolerance. This report represents the first study on integration of a transcriptome analysis to develop molecular markers that are associated with drought tolerance in cotton. [ABSTRACT FROM AUTHOR]

Plants can have detrimental effects on biological control agents by affecting their prey or host quality. Thus, it is important to understand the tri-trophic interactions between plants, herbivores and natural enemies when implementing biological control programmes. Studies have shown that both morphological and chemical traits of host plants can affect the third trophic level. Cotton plants are known to produce alkaloids such as gossypol, a sesquiterpene aldehyde that can confer resistance against herbivorous arthropods. Nevertheless, little is known about the effect of gossypol on biological control agents. In this study, we investigated how three cotton cultivars (BRS Rubi, BRS Safira and BRS Verde) differing in gossypol content affect development and growth of predatory coccinellids,Eriopis connexaandHarmonia axyridis, feeding on the cotton aphidAphis gossypiireared on those cultivars. The results show that the cultivar BRS Rubi (highest gossypol content) had a sub-lethal effect on the development and growth of both Coccinellidae species compared with the other cultivars. Overall, the cultivar BRS Rubi reduced slightly fecundity, net reproductive rate and intrinsic rate of natural increase for both Coccinellidae species. However, because aphid populations stay short periods of time in the field, and adult coccinellids may supplement its diet with alternative prey and plant material this sub-lethal indirect effect of gossypol may not have a detrimental effect on field biological control of cotton aphid by eitherE. connexaorH. axyridis,thus suggesting a compatibility between plant resistance and biological control agents. [ABSTRACT FROM PUBLISHER]

The article focuses on a study related to a comparative assessment of crop phenology, agrometeorological indices and yield of Bt and non-Bt cotton in Maharashtra, India. Topics discussed include obtaining biological yield by summing up seed cotton and stalk yield; requirement of lesser heliothermal unit by cotton hybrid for the appearance of first bud and first flower; and Bt cotton recording higher seed cotton yield than the non-Bt cotton.

This study was conducted in order to obtain information on genetic variation in populations rated as superior cotton (Gossypium hirsutum L.) varieties in Balittas Malang, Indonesia. The samples used 10 varieties of cotton Kanesia series and 2 other superior varieties that are LRA 5166 and ISA 205A. Indicators of genetic diversity are the number of alleles per locus, allele frequencies, and heterozygosity values. DNA was isolated from the leaves of 3-week-old seedlings using the CTAB method. Amplification was performed using 5 SSRs primer pairs of the JESPR series. The results showed five microsatellite loci, yielding 12 alleles with a size range of 80-500 bp, with an average number of alleles per locus of 4.60. The average values of heterozygosity of the five loci was high, at 0.71. Based on the number of alleles, allele frequencies and heterozygosity values, the genetic variation sampled in the superior cotton varieties studied here is quite high. [ABSTRACT FROM AUTHOR]

Much effort has been expended to improve irrigation efficiency and drought tolerance of agronomic crops; however, a clear understanding of the physiological mechanisms that interact to decrease source strength and drive yield loss has not been attained. To elucidate the underlying mechanisms contributing to inhibition of net carbon assimilation under drought stress, three cultivars of Gossypium hirsutum were grown in the field under contrasting irrigation regimes during the 2012 and 2013 growing season near Camilla, Georgia, USA. Physiological measurements were conducted on three sample dates during each growing season (providing a broad range of plant water status) and included, predawn and midday leaf water potential ( Ψ PD and Ψ MD ), gross and net photosynthesis, dark respiration, photorespiration, and chlorophyll a fluorescence. End-of-season lint yield was also determined. Ψ PD ranged from −0.31 to −0.95 MPa, and Ψ MD ranged from −1.02 to −2.67 MPa, depending upon irrigation regime and sample date. G. hirsutum responded to water deficit by decreasing stomatal conductance, increasing photorespiration, and increasing the ratio of dark respiration to gross photosynthesis, thereby limiting P N and decreasing lint yield (lint yield declines observed during the 2012 growing season only). Conversely, even extreme water deficit, causing a 54% decline in P N , did not negatively affect actual quantum yield, maximum quantum yield, or photosynthetic electron transport. It is concluded that P N is primarily limited in drought-stressed G. hirsutum by decreased stomatal conductance, along with increases in respiratory and photorespiratory carbon losses, not inhibition or down-regulation of electron transport through photosystem II. It is further concluded that Ψ PD is a reliable indicator of drought stress and the need for irrigation in field-grown cotton. [ABSTRACT FROM AUTHOR]

[Objective] This study was to analyze the high yielding, stability, adaptability and main characteristics of check cultivars in national cotton regional trials in the Yangtze River Valley in 2000-2013, with the aim to provide theoretical basis for the reasonable selection of check cultivars for cotton regional trials. [Method] GGE biplot analysis method was used to carry out the intensive analysis and comprehensive comparisons on the performances and differences of the 9 major characters of check cultivars, namely, lint cotton yield , stability, and other main traits including boll weight, boll number, lint percentage, fiber length, fiber strength, micronaire value, plant height and seed index. [Result] Ezamian 10 was suitable in the majority of cotton planting regions in the Yangtze River Valley, with the best high yielding ability and perfect yield stability. The yielding ability of Xiangzamian 8 ranked the second, but its stability was the poorest. Xiangzamian 8 was of the specific adaptive cultivar with relatively good performance in high yielding but the poorest stability. The suitable planting areas of Xiangzamian 8 were limited to the cotton planting region around Dongting Lake in Hunan province, Poyang Lake in Jiangxi Province, the Coastal region in Jiangsu Province and Wuhan district in Hubei Province. Xiangzamian 2 performanced poorer in both yielding and stability, while Simian 3 ranked first in stability but the last in yielding ability. The dominant character of Xiangzamian 8 and Xiangzamian 2 were high cotton plants and big bolls. Simian 3 performanced super in lint percentage and fiber length. Ezamian 10 was strong in cotton boll formation ability, lint cotton yielding, fiber strength and seed size, as well as high micronaire value. [Conclusion] The outstanding performance of Ezamian 10 in high and stable yield in the Yangtze River Valley in recent years has effectively promoted the high yielding ability of candidate varieties in cotton regional trials in the area. [ABSTRACT FROM AUTHOR]

Cotton breeders should have knowledge of traits that affect lint yield before embarking on a breeding program. Twelve diverse germplasm lines of upland cotton were used to investigate the effects of lint turnout, days to maturity, boll weight, number of bolls/plant, plant height, number of seeds/boll, boll width, boll length, seed index, number of locs/boll, number of fibers/seed, fiber density, on lint yield. The 12 lines were planted at two locations each during 2011 and 2012 at Stoneville, Miss. Simple correlation coefficients were subjected to path-coefficient analysis and direct and indirect effects were determined. Across all cultivar groups, lint turnout (0.52), plant height (0.43), number of bolls/plant (0.29), and boll weight (0.22) had the highest direct effects on lint yield. They were also positively and significantly correlated with lint yield. Boll length, fibers/seed, fiber density, number of locs/boll, and days to maturity were negatively correlated and with minimal impact on lint yield. Different path relationships between the naked seed and fuzzy seed groups and the okra and non-okra leaf groups were observed. For the okra leaf cultivars, lint turnout and plant height had the highest direct effects on lint yield. For the non-okra group on the other hand, boll weight and plant height had the highest direct effects; boll weight and number of bolls/plant had the highest direct effects on lint yield for the naked seed cultivars, whereas plant height, lint turnout, and boll weight had high direct effects on lint yield for the fuzzy cultivars. [ABSTRACT FROM PUBLISHER]

Lead (Pb) is a toxic heavy metal that causes physiological and morphological changes in plants. Our current study was aimed at observing Pb-induced changes in seeds of two upland cotton varieties (TM-1 and Z-747) that were exposed for 24 hours to various Pb concentrations (0, 50, 100, 300, and 500 µM). Seeds of TM-1 showed higher germination percentages, water uptake, and cell viability as compared to Z-747. Changes in nuclei shape, their partial disappearance, and increase in vacuole size were the initial signs of lead toxicity in Z-747, while TM-1 maintained its typical conformations. Cell wall thickening; increase in the number of mitochondria, protein, and lipid bodies; and vacuolation were more prominent in TM-1. In contrast, plasmolytic shrinkage and scattered cell organelles were the key characteristics of Z-747 at higher doses of Pb. Those observations demonstrated that seeds of TM-1 were more tolerant to Pb stress as compared to Z-747 and may be considered a preferred choice for culture on Pb-contaminated soils. [ABSTRACT FROM AUTHOR]

Current study focused on expression profiling of locally bred Bt-cotton varieties through ELISA and were tested for their efficacy against survival of Helicoverpa armigera in control environment. The population dynamics of five sucking arthropods; whitefly, jassid, aphid, thrips and mites, along the growing season was also monitored and correlated with different meteorological factors. Expression levels of insecticidal protein CrylAb/c were found to vary significantly (P<0.05) among varieties and across different sampling dates. The highest mean expression was recorded in GN-31 and Sitara-008 and the lowest in FH-113 and MG-6 while across sampling dates the highest mean expression was recorded at 30 days after emergence (DAE) which decreased along the season with lowest mean at 120 DAE. A critical expression level of Cryl Ab/c in leaves was found at 770 ± 25 ng g[sup -1], for 95% control of the target insect pests. Sucking pest population was found to be variable among both the cultivars and the sampling dates. A positive correlation was found between rain/ humidity and sucking arthropods population in the sampled cotton plots. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]

Dusky bug (Oxycarenus laetus) and red cotton bugs (Dysdercus koingii) are commonly known as seed bugs because they feed on cotton seed. They have become major threat to cotton in Pakistan since last two years. The present studies were therefore planned to find out the role of sowing dates in cotton pest population. The dusky and red cotton bug population varied considerably with respect to date of sowing. The results revealed that invasion of both bugs was significantly more in case of early sowing ( up to 15 red cotton bug/plant & 25 dusky bugs/boll) than in normal and late sowing (8 to 10 red cotton bugs & 10 to 12 dusky bug/boll respectively). Sampling dates exhibited that population of cotton bugs (dusky and red cotton bug) was higher during first week of October followed by mid September, 2013, whereas lower in late sowing. Varietal comparison depicted that FH-118 and FH- 142 showed non significant difference for red and dusky cotton bug population. The results further explained that peak population of red cotton bug was recorded during the month of October, 2013. [ABSTRACT FROM AUTHOR]

The breeding program of Giza 87 was conducted at Sakha Agricultural Research Station, Kafr El-Sheikh district during 2010 -2013 growing seasons. In 2010 season sixty type plants were selected from the .breeding-field of Giza 87 variety and furnished sixty progenies (increase A) in 2011. From the later, seventeen families were sêledted to descend increase B in 2012. According to the statistical analysis of yield trial which included the seventeen families and comparisons of the latest lines of Giza 87, six elite families were selected and the seeds were carefully massed together to form the nucleolus (breeder's seed) in 2013 season. The results obtained indicated that, the pure line method in the sense of pedigree selection for renewing annually Giza 87 breeder's seed could produce high genetically pure seeds and in the same time, prevent genetic contamination. Meanwhile, the selection technique for producing breeder's seed of Giza 87 variety was valid and proved to be effective in holding this variety according to the standard type of Giza 87. [ABSTRACT FROM AUTHOR]

Relationships between lint yield and within-boll yield components are important for genetic improvement of lint yield in cotton ( Gossypium hirsutum L.) cultivars. F plants derived from crosses between germplasm lines and high yielding cultivars were analyzed to determine the contributions of within-boll yield components to lint yield and to select parents with desirable combining ability for multiple within-boll yield components. Forty-five F hybrids were planted at two field sites in 2010 and 2011 with 4 and 3 replicates, respectively. There were a total of six yield components analyzed including lint percentage (LP), seed number per boll, lint weight per seed (LW_S), seed surface area per seed, lint weight per unit seed surface area (LW_SA), and lint number per unit seed surface area (LN_SA). The contributions of these yield components to lint yield were analyzed by commonality analysis that separated the contributions to lint yield into the unique contributions of single yield components and the common contributions of the single yield components with one or more other yield components. The unique contributions of the six yield components to lint yield ranged from 1.6 to 21 % of total variation for lint yield in the 2-year experiments. The greatest common contributions to lint yield among all combinations of the six yield components were identified for a combination of four components, LP, LW_S, LW_SA, and LN_SA with 67 and 44 % of the total variation of lint yield in 2010 and 2011, respectively. Results suggest that all four of these yield components should be considered simultaneously in breeding for genetic improvement of lint yield. The germplasm line SP225 was detected as a good combiner with positive general combining ability (GCA) for LP (1.4 %), LW_SA (0.03 mg mm), and LN_SA (14.3 no mm), and favorable GCA for fineness (−3.1 mg km). [ABSTRACT FROM AUTHOR]

Glandless cotton can be grown for cottonseed free of toxic gossypol to be used as food and feed for non-ruminant animals. However, one of the most important limiting factors preventing its commercial production is its higher insect damage than conventional glanded cotton. Thrips is the one of the most important insect pests in the early growing season that may cause yield losses. In this study, 28, 29, 26, and 2 glandless cotton lines were compared with glanded control Acala 1517-08 and other glanded lines for resistance to the Western flower thrips, Frankliniella occidentalis (Pergande) in four replicated field tests each containing 32 genotypes. In the same field, 28 glanded commercial cultivars and 78 glanded breeding lines were compared with Acala 1517-08 and Acala 1517-99 in three other tests with 32 genotypes each. The experimental layouts allowed a comprehensive comparative analysis of thrips resistance within and between glandless and glanded cotton. Overall, glandless cotton had similar or lower thrips damages than glanded cotton, indicating that the glandless trait may serve as a genetic factor for suppressing thrips damage. As compared with Acala 1517-08 which represented one of the most thrips resistant genotypes among glanded cotton tested, glandless Acala GLS and many selections from glandless germplasm were more resistant, while some were similar to Acala 1517-08, indicating that genetic factors other than the glandless trait also affect thrips resistance in cotton. The estimates for broad-sense heritability for thrips resistance were moderate, indicating that thrips resistance is selectable. This is corroborated by the identification of many thrips resistant lines from a cross between Acala 1517-08 and Acala GLS. This study has laid a foundation for a more detailed study using most resistant lines with desirable agronomic traits in multiple environments. [ABSTRACT FROM AUTHOR]

DNA of 15 cotton genotypes comprising five parents and their ten F hybrids was extracted successfully from their immature leaves 1 to estimate genetic diversity and hybrid identification. Out of the 26 RAPD primers used for DNA amplification, 14 primers produced polymorphic bands, while 12 produced monomorphic bands. These 14 primers yielded total 96 RAPD markers, out of which only 40 were found polymorphic which resulted in 41.66% polymorphism among the genotypes studied. The number of RAPD markers produced ranged from 4 to 12. Average number of 6.40 bands per primer was observed. On the whole, 87.50% genetic identity was found in material under investigation and it ranged from 68.07% to 96.88%. The polymorphism detected among the genotypes was employed as marker for hybrid identification. Comparing the banding patterns of RAPD of the parents with their particular hybrids, true hybrids were identified by six primers namely GLA-7, GLA-8, GLA-15, GLA-19, GLD-3 and GLD-5. Consequently, RAPD analysis can be used as a marker technique to ascertain the hybrid nature of offsprings and to evaluate parental lines in terms of genetic diversity. [ABSTRACT FROM AUTHOR]

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Bacterial seed and boll rot is a newly emerging cotton disease in Pakistan. Twenty-one cotton varieties were screened to find resistance source against the disease. None of these was found to be resistant. Five cotton varieties (CIM-595, MK2, BT-986, BT-986 & SG-1) having 700–1400 Area under disease progress curve (AUDPC) units were found to be moderately resistant to the disease. SLH-317, FH-942, BT-222, BT-666, MNH-457 ranging from 1401–1700 AUDPC units were moderately susceptible while MNH-456, SLH-336, 9811, FH-942, MNH-886 susceptible to boll rot. Seven varieties (FH-114, FH-113, BT-7, BT-212, SLH-BT-4, BT-212 and FH-941) were highly susceptible to bacterial seed and boll rot indicated by 2001–2300 AUDPC units. Biochemical tests identified bacterial isolates asPantoea agglomerans. Different inoculation techniques were assessed for bacterial pathogenicity and symptoms of boll rot were only observed in needle punctured bolls. One, two and three weeks old bolls were mechanically inoculated by injecting bacterial suspension to evaluate the boll’s age impact on disease severity. Maximum severity was observed in two weeks old bolls. Red cotton bugs (Dysdercus cingulatus) were fed on artificially inoculated diseased bolls and then transferred on healthy bolls. Diseased symptoms were noticed on healthy cotton bolls. Bacterial colonies were recovered and red cotton bug was confirmed as the disease-transmitting vector. [ABSTRACT FROM AUTHOR]

[Objective] Based on the cotton variety high yielding potential, fiber quality traits, disease resistance, and early maturity characters, a cultivar registration index model was developed to simplify the tedious calculation process in national cotton registration procedure, and thus to enhance the practical application of cultivar registration index in cotton breeding and cotton recommending. [Method] By means of correlation analysis, partial correlation analysis and path analysis methods, the correlation of cotton main properties and their effects on cultivar registration index were explored using the dataset of national cotton regional trials in Yangtze River Valley during 1996-2013. The cultivar registration index model was constructed with stepwise regression statistical technique to ascertain the quantitative relationship of main characters with cultivar registration index, and the regional cotton trial dataset in 2013 was used to validate the model. [Result] Several characters with larger determinants to cultivar registration index were screened out, i.e. lint yield increase ratio, pro-frost yield ratio, verticillium wilt index, fiber strength, fusarium wilt index and micronaire value. The cultivar registration index model defined the functional relationship of cultivar registration index with the selected main characters, among which lint yield increase ratio, fiber strength and micronaire value contributed most to cultivar registration index. The model validation with regional cotton trials in 2013 indicated the root mean square error, RMSE was only 2.77, and the variation coeff icient was 6.77%, which confirmed the model prediction effect was quite perfect. [Conclusion] The developed cultivar registration index model was reliable enough to simulate the complicated scoring system in cultivar registration procedure, also simplified cotton registration process, and enhanced the practicability of the cultivar registration index. [ABSTRACT FROM AUTHOR]

Perennial forms of Gossypium hirsutum are classified under seven races. Five Mesoamerican races would have been derived from the wild race ‘yucatanense’ from northern Yucatán. ‘Marie-Galante’, the main race in the Caribbean, would have developed from introgression with G. barbadense. The racial status of coastal populations from the Caribbean has not been clearly defined. We combined Ecological Niche Modeling with an analysis of SSR marker diversity, to elucidate the relationships among cultivated, feral and wild populations of perennial cottons. Out of 954 records of occurrence in Mesoamerica and the Caribbean, 630 were classified into four categories cultivated, feral (disturbed and secondary habitats), wild/feral (protected habitats), and truly wild cotton (TWC) populations. The widely distributed three first categories cannot be differentiated on ecological grounds, indicating they mostly belong to the domesticated pool. In contrast, TWC are restricted to the driest and hottest littoral habitats, in northern Yucatán and in the Caribbean (from Venezuela to Florida), as confirmed by their climatic envelope in the factorial analysis. Extrapolating this TWC climatic model to South America and the Pacific Ocean points towards places where other wild representatives of tetraploid Gossypium species have been encountered. The genetic analysis sample comprised 42 TWC accessions from 12 sites and 68 feral accessions from 18 sites; at nine sites, wild and feral accessions were collected in close vicinity. Principal coordinate analysis, neighbor joining, and STRUCTURE consistently showed a primary divergence between TWC and feral cottons, and a secondary divergence separating ‘Marie-Galante’ from all other feral accessions. This strong genetic structure contrasts strikingly with the absence of geographic differentiation. Our results show that TWC populations of Mesoamerica and the Caribbean constitute a homogenous gene pool. Furthermore, the relatively low genetic divergence between the Mesoamerican and Caribbean domesticated pools supports the hypothesis of domestication of G. hirsutum in northern Yucatán. [ABSTRACT FROM AUTHOR]

Bt-transgenic cotton has proven to be highly efficient in controlling key lepidopteran pests. One concern with the deployment of Bt cotton varieties is the potential proliferation of non-target pests. We previously showed that Bt cotton contained lower concentrations of insecticidal terpenoids as a result of reduced caterpillar damage, which benefited the aphid Aphis gossypii. It is thus important that non-target herbivores are under biological control in Bt cotton fields. The induction or lack of induction of terpenoids could also influence the quality of aphid honeydew, an important food source for beneficial insects. We therefore screened A. gossypii honeydew for cotton terpenoids, that are induced by caterpillars but not the aphids. We then tested the influence of induced insect-resistance of cotton on honeydew nutritional quality for the aphid parasitoid Lysiphlebus testaceipes and the whitefly parasitoid Eretmocerus eremicus. We detected the cotton terpenoids gossypol and hemigossypolone in A. gossypii honeydew. Although a feeding assay demonstrated that gossypol reduced the longevity of both parasitoid species in a non-linear, dose-dependent manner, the honeydew was capable of sustaining parasitoid longevity and reproduction. The level of caterpillar damage to Bt and non-Bt cotton had no impact on the quality of honeydew for the parasitoids.These results indicate that the nutritional quality of honeydew is maintained in Bt cotton and is not influenced by induced insect resistance. [ABSTRACT FROM AUTHOR]

The pathogenicity of eight isolates of Rhizoctonia solani from different anastomosis groups was evaluated on five cotton (Gossypium barbadense L.) cultivars under greenhouse conditions. Damping-off, plant height and fresh weight were used as criteria to evaluate pathogenicity. Analysis of variance (ANOVA) showed that the cultivar and cultivar x isolate interaction were always non-significant sources of variation in all the tested parameters. The isolate was always a highly significant (P=0.000) source of variation in all the tested parameters. The results of the ANOVA in the present study suggest that physiologic specialization did not occur within R. solani isolates pathogenic on cotton. They also imply that resistance of the tested cultivars was only horizontal, and there were no significant differences among cultivars in this type of resistance. Similarly, pathogenicity of the tested isolates was only aggressiveness, and the isolates significantly differed in this type of pathogenicity. A hierarchical cluster analysis was conducted in order to group the isolates according to disease variables measured on the tested cultivars. Cluster analysis divided the isolates into groups; however, grouping the isolates was not related to their AGs. [ABSTRACT FROM AUTHOR]

The present studies were aimed to characterize the early maturing cotton genotypes and determine the relationship among earliness, yield and fiber quality traits. Eight upland cotton genotypes viz., CRIS-134, Sadori, Chandi, NIAB-78, AA-802, IR-3701, IR-1524 and FH-113 were included in the studies. The experiment was laid out in a randomized complete block design with four replications during 2012 at Sindh Agriculture University, Tandojam, Pakistan. The mean squares indicated significant (p=0.01) differences among the genotypes for all the traits. The two cultivars i.e. CRIS-134 and Sadori were characterized as early maturing in terms of days to 1st flower, formed sympodial branches at relatively lower nodes, set 1st effective boll on lower sympodia, formed and opened maximum bolls at 90 and 120 days after planting (DAP) and weighed medium size bolls. For yield traits, maximum bolls plant-1, bigger bolls, higher seed cotton yield and more lint percentage were obtained from cultivars CRIS-134, Sadori, IR-3701 and FH-113. Regarding fiber traits, the longer staple with desirable micronaire were recorded by CRIS-134, AA-802 and FH-113. The correlation coefficient showed that sympodial branch length, bolls formed at 120 DAP, bolls plant-1 and seed index were significantly and positively correlated with seed cotton yield. The higher correlations of yield components with yield indicated their reliable use as indirect selection criteria to improve the seed cotton yield. Some important negative correlations of lint percentage with seed index, staple length and micronaire value were also recorded which indicated that a compromise level for lint percentage may be considered while improving staple length and fiber fineness in cotton. [ABSTRACT FROM AUTHOR]

[Objective] This study was to evaluate the high yielding and stability of candidate cultivars, depict the adaptive planting region, analyze trial location discrimination ability and representativeness, as well as identify the ideal cultivar and trial location, with the aim to provide theory background for cultivar selection and reasonable scheme of test location in Jiangsu Province. [Method] The GGE biplot method was used to analyze the lint cotton yield of 12 experimental genotypes in the 6 test locations(three replicates in each) of the cotton regional trial in Jiangsu Province in 2013. [Result] The effects of genotype(G), environment(E), and genotype by environment interaction(G×E) on lint cotton yield were all highly significant(P<0.01), which made it necessary to further explore the specific pattern of genotype by environment interaction. Jinmian118(G4) and SF3303(G5) were the best ideal genotypes screened by the "ideal cultivar" and "ideal location" view of GGE biplot, and the ordination of test sites based on the ideal index were in the order of Dafeng (DF), Yanliang (YL), Liuhe (LH), Dongtai(DT), Yancheng (YC), and Nantong (NT), among which NT was relatively weak in representing of the whole target cotton planting region in Jiangsu Province. The "similarity among locations" view of GGE biplot clustered all trial locations into one group, showing that the test sites in the cotton planting region in Jiangsu Province were in the same mega-environment. The "which-won-where" view of GGE biplot indicated that cotton cultivar Jinmian118 (G4) was the most appropriate cultivar in the homogeneous cotton planting region in Jiangsu Province. [Conclusion] Among the candidate cultivars, Jinmian118 and SF3303 were identified as the most ideal cultivars in this set of conventional cotton regional trial in Jiangsu Province; the test site of Dafeng ranked the first out of all locations in terms of discrimination and representativeness, and all test locations were clustered into the same mega-environment, which indicated the high efficiency of cultivar selection in the cotton regional trial in Jiangsu Province. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the functional response of Orius insidiosus preying on the third and fourth instars of Aphis gossypii nymphs that were reared on transgenic NuOPAL (Bollgard I Event 531) and conventional Buriti cotton varieties. Fifty O. insidiosus female bugs aged 12-24h were distributed into five different Petri dishes with different densities of A. gossypii (2, 4, 8, 16, and 32 nymphs per plate) for each cotton variety. The number of prey consumed was evaluated over the course of 12h, with a final assessment at 24h. The handling times (Th) and attack rates (a) were 0.0697h and 1.1862h-1, respectively, for the Buriti variety and 0.0713h and 0.3030h-1, respectively, for the NuOPAL variety. The average number of prey consumed by O. insidiosus was similar for both varieties at 24h and at higher densities; the attack rate was higher for the Buriti-reared aphid prey than for the NuOPAL-reared aphids. [ABSTRACT FROM AUTHOR]

Markets for organically produced high quality cotton (Gossypium hirsutum L.) are projected to increase. Field experiments were conducted to compare the effects of two cropping systems on seed and lint yield and fiber quality of three cotton cultivars. The experiments, conducted during 2008, 2009, and 2010, were laid out in a split plot design with four replicates, two main plots (organic and conventional system) and three subplots (cotton cultivars: Athena, Alexander, and Fandom). The organic system resulted to a seed cotton yield at greater or same levels than the conventional system. Micronaire values and maturity for all the cultivars at 2009 and 2010 were satisfactory, while fiber length did not differ between cropping systems, except in 2009. Elongation of the fiber differed among cropping systems only in 2010 and Fandom had the highest rate of fiber elongation. For the organic and conventional systems, fiber strength reached values of 34.47 and 32.5 g tex-1, respectively. Short fiber index declined throughout the 3-yr period in the organic system. This study confirmed that organic cultivation does not negatively affect lint yield or fiber quality, while in the same time it also produced high seed yield. Findings suggest that despite the significant role of genotype, the interactions of year with cultivar and cropping system have a decisive impact on fiber quality. [ABSTRACT FROM AUTHOR]