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To identify homoeologous group-3 chromosomes that carry genes for vernalization, day-length responses, and earliness per se, a series of aneuploid lines (mono- somics and tetrasomics) and chromosome-substitution lines in 'Chinese Spring' (CS) were surveyed under different vernalization and day-length regimes in controlled environments. The results indicated that genes on all three chromosomes of group 3 can have striking effects on ear-emergence time, The replacement of CS 38 by its homologues in 'Lutescens 62' and 'Cheyenne' produced an increased Insensitivity to vernalization, while 3B homologues from 'Ceska Presivka' gave CS a remarkable sensitivity to vernalization. This provided evidence for multiple allelism at a new Vrn locus on chromosome 3B. A negative association between gene dosage and day-length response was found an CS 3D which was thought to carry a gene for promoting insensitivity to day- length The behaviour of CS monosonic 3A and CS (Timstein 3A), in reducing numbers of days to heading independently of environmental stimuli, suggested the presence of earliness per se genes on this chromosome. [ABSTRACT FROM AUTHOR]

The inheritance of earliness and fruit weight in tomato was studied in four interspecific crosses. Two cultivated varieties, i.e. 'HS 101' and 'HS 102', were hybridized with two wild species, L. hirsutum f. glabratum 'B 6013' and L. pimpinellifolium 'A 1921'. Six generations of these crosses were evaluated for these traits and the estimates of gene effects were derived from the generation mean using an epistatic (six parameters) model. There were very wide differences between cultivated and wild species for earliness and fruit weight and in the segregating populations, plants with delayed maturity and smaller fruit size were recorded with high frequency. It was found that the inheritance pattern was mainly governed by additive gene action. Epistatic effects also contributed towards the inheritance of both traits. [ABSTRACT FROM AUTHOR]

A yellow-seeded exotic accession of Brassica juncea has shown complete freedom from white rust and powdery mildew and a high degree of resistance to Alternaria black spot under conditions of heavy disease infestation in the field. The germplasm line was, however, too late in flowering and maturity to be useful for either processing directly into a variety or to be involved in a crossing programme for breeding. Somaclonal variation from this accession has provided a highly productive line which retains the resistance to diseases of the parental material. [ABSTRACT FROM AUTHOR]

The adaptability of wheat cultivars to environmental conditions is known to be associated with a vernalization requirement, that is, spring/winter habit. To clarify the genetic effect of the spring habit gene, Vrn-D1, on heading time in the field, recombinant inbred lines (RILs) with or without the Vrn-D1 gene were produced from F2 plants of the cross between ‘Nanbukomugi’ and ‘Nishikazekomugi’, non-carrier and carrier cultivars of this gene, respectively. Using growth chambers with a controlled temperature and photoperiod, three components of heading time, i.e. vernalization requirement, photoperiodic sensitivity and narrow-sense earliness (earliness per se), were evaluated in each RIL. RILs with the Vrn-D1 gene (E lines) showed greatly reduced vernalization requirements and slightly shorter narrow-sense earliness than RILs without Vrn-D1 (L lines), although no difference in photoperiodic sensitivity was observed between the two groups. RILs were planted at four different sites in Japan and examined for their heading time in the field. E lines headed significantly earlier than L lines at all locations, indicating that the earliness of E lines is stable in various environmental conditions. These results indicated that spring habit caused by Vrn-D1 gene, as well as narrow-sense earliness, was responsible for heading time in the field. [ABSTRACT FROM AUTHOR]

Thirty-nine barley varieties of different origin, representing different growth types, were included in a series of experiments aimed at analysing the variability in vernalization response, photoperiod sensitivity and earliness per se and establishing the types of ecoclimatic adaptability using multivariate analysis. In the case of spring barley varieties there was no correlation between any of the three traits. For winter barleys, a negative correlation was found between photoperiod sensitivity and vernalization response and between photoperiod sensitivity and earliness per se. Vernalization response and earliness per se showed a positive correlation. Among the winter barley varieties large variations were apparent in photoperiod sensitivity, vernalization response and earliness per se, which resulted in a tremendous variation in flowering patterns and frost tolerance. Between the spring barley varieties only wider variations in photoperiod sensitivity were detected. Based on the cluster analysis, the 39 varieties could be separated into seven groups. The spring barley varieties were placed in two groups, and the winter barleys in five groups representing different adaptational types. Among these five groups two represented the two opposing extreme combinations of photoperiod sensitivity and vernalization response. The combination of large photoperiod sensitivity and no vernalization response resulted in better frost tolerance than did the combination of photoperiod insensitivity and large vernalization response. [ABSTRACT FROM AUTHOR]

The inheritance of heading time of spring barley was studied in three extremely early genotypes IB, RL and ‘Mona’ (M), which is homozygous recessive for the early maturity ea8 (= eak) gene conferring extreme earliness under short daylengths and is relatively photoperiod insensitive, and five (GP, MA, PS, NU and BA) spring genotypes that are early to intermediate for heading time. Frequency distributions of F2 generations grown at Ouled Gnaou, Morocco (32°15′ N), an environment which maximizes differences between photoperiod-insensitive and photoperiod-sensitive genotypes, indicated that across populations many loci were segregating in a complex Mendelian manner. IB and RL were both homozygous recessive for the ea8 gene, which conferred an early heading time. RL had partially dominant alleles at second locus (Enea8), which enhanced its earliness. Recovery of only progeny within the parental range of genotypes for heading time from the crosses of RL/M and IB/M suggests that numerous loci remained suppressed, perhaps latent, given their diverse parentage. The ea8 recessive homozygote in RL suppressed another unidentified locus which, when homozygous recessive in the absence of the ea8 recessive homozygote, conferred extreme earliness in one short daylength environment (Ouled Gnaou, Morocco) but was undetected in another environment (Davis, CA, USA). Epistatic gene action and genotype × environment effects strongly influenced heading time. In addition to a genetic system consisting of single-locus recessive homozygotes conferring photoperiod insensitivity, a second genetic system, based on dominant alleles at one or a few loci, derived from the early heading Finnish landrace ‘Olli’, also confers extremely early heading time under short daylengths and relative photoperiod insensitivity in the genotype GP. [ABSTRACT FROM AUTHOR]

Associations of 23 quantitative traits and 10 genetic marker characters were examined in 63 chromosome-doubled lines (DH-lines) derived from the F1-generation of a cross between an old and a modern spring barley variety. One fourth of the marker × trait combinations showed significant associations. More than two thirds of these associations were to earliness (heading date). Earliness was found to be controlled by two loci: the previously known eak locus and a new locus designated Ea,,. It is concluded that the associations of quantitative traits with the earliness loci were caused by pleiotropy. Associations were found between two absolutely linked C-bands on chromosome 3 and QTLs (quantitative trait loci) for lodging, straw diameter, and length of top internode of the straw. The three loci on chromosome 5, eak and the two linked powdery mildew loci, M1a9 and Mlk, were associated with a possible QTL for magnesium concentration in grain. Association to the C-band on chromosome 6 suggests QTLs for TGW (thousand grain weight), straw diameter and magnesium concentration in grain. Locus Est1 on chromosome 3 was not associated with any of the quantitative traits. [ABSTRACT FROM AUTHOR]

Copyright of Plant Breeding is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

QEet.ocs-5A.1 , a quantitative trait locus controlling ear emergence time, has been detected on wheat chromosome 5AL using single chromosome recombinant lines (SCRs) developed from a cross between `Chinese Spring' (CS) (`Cappelle-Desprez' 5A) and CS (Triticum spelta 5A). This locus has little influence on grain yield and its components, and thus has breeding potential for changing ear emergence time without yield reduction. To characterize the phenotypic expression of QEet.ocs.1 and to test its interaction with the Vrn-A1 gene for vernalization response, six near-isogenic SCRs differing for these two gene regions were grown together with the parental controls under different vernalization and photoperiod regimes. The T. spelta allele of QEet.ocs.1 accelerated heading time when vernalization and photoperiod were satisfied, demonstrating that the function of this QTL is earliness per se . There was no interaction between Vrn-A1 and QEet.ocs.1 . [ABSTRACT FROM AUTHOR]

Copyright of Plant Breeding is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Pigeonpea breeding activities started about a century ago and for decades only late maturing cultivars dominated the global cultivation. Historically, no early maturing cultivar was available for a very long time and breeding of such varieties started in the third quarter of 20th century but at a low key. From these efforts, some pigeonpea varieties maturing in 90–150 days were bred. Information gathered from various sources revealed that the first few early maturing genotypes originated through spontaneous mutations in the late maturing field‐grown landraces. In other cases, transgressive segregation and induced mutations also produced early maturing varieties. At present, the high yielding early maturing cultivars are contributing significantly towards widening the adaption barriers and in the diversification of some age‐old cropping systems. In this paper, the authors, besides discussing the importance of early maturing cultivars in present agricultural systems, also summarize information related to the origin of primary sources of earliness. [ABSTRACT FROM AUTHOR]

The extension of the ripening season in open field production is of high economic interest for strawberry growers. Therefore, targeted breeding for extreme early or late ripening cultivars with high yield potential is of particular interest. Thirteen strawberry cultivars were crossed in a reciprocal way without selfing, and the 144 resulting F1 populations were evaluated in a field trial over a period of two consecutive years. The data were analysed using a mixed-model approach adapted for diallel crossing designs using SAS 9.3. The variability in the crossing approach is mainly based on the general combining ability ( GCA) of the cultivars (additive effects). Specific and reciprocal combining abilities (non-additive effects) appear less important. The highest GCAs for the trait Marketable Yield were found for the cultivars ' Polka' and ' Yamaska'. The trait Earliness is bilateral with significantly low GCAs for early ripening in ' Clery' and ' Daroyal' and significantly high GCAs for late ripening in ' Yamaska' and ' Florence'. Crosses with these cultivars are likely to deliver populations with both high yield and an extended ripening period. [ABSTRACT FROM AUTHOR]

Fonio production is generally in polyvarietal mixture and no improved varieties are available yet. This work proposed a pathway for homogenization and mass selection from 19 accessions previously collected in Benin, to sort best genotypes. From 2015 to 2017, accessions were submitted to homogenization followed by separated conduct of different phenotypes appeared each year. Each material was evaluated on elementary plot of 3 m2. Agro‐morphological data collected were submitted to descriptive and multivariate analyses. Results showed homogeneity and selection effectiveness varied following characters and accessions. Better homogeneity level was obtained on qualitative characters compared to morphometric traits. Selection led to derivative accessions earlier or more productive than their parents. Thus, compared to parents, shortenings of 10%–30% on plant cycle and progress of 10%–70% in yield were recorded for some derivative accessions. On grains colour, 86% of accessions are homogeneous from 70% to 100%. Three groups characterized by earliness, productivity and grains homogeneity were identified. AS19‐1‐1, AS1, AS13‐1, AS2‐1‐1, AS15‐1‐1 and AS18 were sorted genotypes. Multi‐local assessments will be conducted for homogeneous and efficient ideotypes responding farmer's needs. [ABSTRACT FROM AUTHOR]

With 1 figure and 3 tables Time of flowering is an important component of adaptation and productivity of chickpea (Cicer arietinum L.) in semi‐arid environments characterized by terminal drought and heat stress. Genetics of flowering time was studied in late × early, early × late and early × early crosses under field conditions to obtain additional information on the number of genes involved and their allelic relationships. Results have shown that duplicate dominant genes with cumulative but unequal effect govern flowering time in chickpea. A genotype with two dominant alleles in homozygous or heterozygous conditions at both loci (Efl1,Efl2) control late flowering (41 days and above). A genotype with a dominant allele in homozygous or heterozygous condition at one of the loci and homozygous recessive allele at the other (Efl1,efl2) control earliness (26–40 days) and a genotype with homozygous recessive alleles at both loci (efl1,efl2) is responsible for super‐earliness (<25 days). Influence of maternal genetic factors on the inheritance of flowering time was non‐significant in chickpea. [ABSTRACT FROM AUTHOR]

Sixteen-hundred BC[sub 1] plants of a cross between an early blight (EB) susceptible tomato (Lycopersicon esculentum Mill.) breeding line ('NC84173'; maternal and recurrent parent) and a resistant accession ('PI126445') of the tomato wild species Lycopersicon hirsutum Humb. and Bonpl. were grown in a field in 1998. This population was segregating (among other traits) for growth habit, self-incompatibility and earliness in maturity. To eliminate confounding effects of these factors on disease evaluation and h[sup 2] estimation, plants that were self-incompatible, indeterminate and/or late-maturing were eliminated. The remaining plants (146), which were self-compatible and determinate (sp./sp.) in growth habit, with early- to mid-season maturity, were evaluated for EB resistance and self-pollinated to produce BC[sub 1]S[sub 1] seed. The 146 BC[sub 1]S[sub 1] progeny families, consisting of 30 plants per family, were grown in a replicated field trial in 1999 and evaluated for EB resistance and plant maturity. For each of the 146 BC[sub 1] plants and corresponding BC[sub 1]S[sub 1] families, the area under the disease progress curve (AUDPC) and final disease severity (final percentage defoliation) were determined and used to measure disease resistance. The distributions of the AUDPC and final percentage defoliation values in the BC[sub 1] and BC[sub 1]S[sub 1] generations indicated that resistance from 'PI126445' was quantitative in nature. Estimates of h[sup 2] for EB resistance, computed by correlation between BC[sub 1]S[sub 1] progeny family means and BC[sub 1] individual plant values, ranged from 0.69 to 0.70, indicating that EB resistance of 'PI126445' was heritable. Across BC[sub 1]S[sub 1] families, a small, but significant, negative correlation (r =-0.26, P < 0.01) was observed between disease resistance and earliness in maturity. However, several BC[sub 1]S[sub 1] families were identified with considerable EB resistance and reasonably early maturity. These... [ABSTRACT FROM AUTHOR]

The objective of this study was to induce semidwarf, early maturing and blast resistant mutants in two adapted Indian rice cultivars. Seeds of the rice cultivars `Madhu Malti' and `Phul Patas 72' were treated with gamma rays and ethyl methane sulfonate (EMS) as well as a combination of gamma rays and EMS. A total of 96 dwarf (c 75 cm) and semidwarf (<100 cm) and 104 early flowering/maturing M2 plants were identified among the 18,060 M2 plants observed. Sixty-eight blast resistant M2 plants were also identified. The true mutant status of these plants has yet to be determined in progeny tests. The induction of desired mutant types in locally adapted cultivars could prove to be superior over their introduction from non-adapted foreign materials via backcrossing in that the important agronomic characteristics of adaptation to the local environment are retained in the mutants. [ABSTRACT FROM AUTHOR]

Several studies have indicated a possible link between genome size and earliness in maize. In this study, an original maize population, South African photo-period insensitive maize composite II (C[SUB0]) and several selected generations were analyzed for days to flowering, plant height, ear height, and yield. The selection criterion was earliness. Over six cycles of selection a 14-day decrease in days to flowering was obtained with no significant reduction in grain yield. In the initial population (C[SUB0]) and the most advanced selection (C[SUB6]) 101 plants were analyzed for nuclear DNA content. A significant decrease in the mean nuclear DNA content of the C[SUB6] population (102 AU) was observed with respect to the C[SUB0] population (105 AU). This reduction was the result of a decrease in frequency of plants in the C[SUB6] population with large genome sizes. Therefore it was concluded that selection for earliness resulted in selection against plants with large genome sizes. Hence, the nucleotype of a maize plant can be modified by selection such as early flowering time. [ABSTRACT FROM AUTHOR]

A core subset of Spanish durum wheat landraces was evaluated at two nitrogen levels (80 and 220 kg/ha) to identify landrace genotypes adapted to low N production. Yield differences were statistically significant between N levels and among genotypes at both levels. Fifty-one per cent of the landraces yielded significantly more at low than at high N (low-N varieties) while 26% had a positive (high-N varieties) and 23% an indifferent (indifferent-N varieties) response to N fertilizer. No significant agromorphological differences were found among low and high-N varieties at low N level that conferred some advantage to low-N varieties. In contrast, high-N varieties possessed longer grain-filling period under high N level. Phenological characters showed an important influence on yield and on the performance of the varieties within each subgroup. The traits affecting grain yield most positively, mainly the low-N varieties, were long filling period and earliness. Five entries were selected for prebreeding to low N adaptation. [ABSTRACT FROM AUTHOR]

Einkorn harbours a wide range of genetic diversity for agronomically important traits. Heading date is one of the important traits for the adaptation of wheat species to various climatic conditions and the cultivation in diverse regions and seasons. In this study, DArTseq and SSR marker‐based linkage map of einkorn wheat was constructed using 150 recombinant inbred lines (RILs) derived from a cross between ID1623 and MONLIS. The linkage map involved 865 SNP, 787 Silico‐DArT and 16 SSR DNA markers mapped to 741 loci in seven linkage groups and covered 1158.54 cM with an average density of 1.56 cM/locus. Four QTLs associated with heading date, detected in all environments by composite interval mapping (CIM), were positioned across the 2A, 5A and 7A einkorn wheat chromosomes. Two major and stable QTLs, QThd‐2A.2 and QThd 5A.1, were identified on chromosomes 2A and 5A, respectively. These QTLs probably coincide with photoperiod and vernalization genes in accordance with previously published maps. The new map will facilitate quantitative trait locus mapping, map‐based cloning and comparative genomics in wheat species. [ABSTRACT FROM AUTHOR]

Genetic diversity is considered as one of the criteria for the selection of parents for hybrid breeding. The present study was undertaken to evaluate genetic divergence among seven pepper cultivars and to assess the relationship between heterosis and parental genetic distance. Twenty-one F1 hybrids and seven parents were evaluated for 15 morphological characters in a greenhouse and in the field. The parents were examined for DNA polymorphisms using six amplified fragment length polymorphism (AFLP) primer combinations. Cluster analysis using two genetic distance measures grouped the seven parents differently. Mid-parent and high-parent heterosis was observed for most characters. Most hybrids outperformed the parental lines for fruit yield, earliness and plant height. Morphological and AFLP-based distance measurements were efficient enough to allocate pepper genotypes into heterotic groups. The correlations of morphological distances with mid-parent heterosis were significant for days to flowering and maturity, suggesting earliness can be predicted from morphological distances of parental lines. However, the correlations of AFLP-measured genetic distances with mid- and high-parent heterosis were non-significant for all characters, except for fruit diameter, and proved to be of no predictive value. [ABSTRACT FROM AUTHOR]

A dwarfing effect of the 44.1 cM chromosomal region between the threshability gene Q and Xfba068 on the long arm of hexaploid wheat chromosome 5A has been reported. To clarify whether Q or its adjacent region is responsible for regulating culm elongation, two precise genetic stocks of near-isogenic lines (NIL), a single chromosome substitution line, ‘Chinese Spring’ (CS; ‘Cappelle-Desprez’ 5A) (NIL- Q) and a single chromosome recombinant substitution line (NIL- q) were used. The target segment of NIL- q included the q allele and QEet.ocs-5A.1, an earliness per se gene, from spelt wheat in the CS genetic background. They were grown under 16-h day length with and/or without vernalization treatment. Being independent of heading date, NIL- Q showed shorter elongation in lower internodes and decreased internode differentiation in comparison with NIL- q. The culm-length reduction associated with Q was confirmed in the recombinant F5 population derived from the cross between NIL- Q and NIL- q. Vernalization promotion had a tendency to reduce this dwarfing effect. [ABSTRACT FROM AUTHOR]

Resistance in oats ( Avena sativa L.) to Fusarium graminearum was phenotyped in 424 spring oat lines from North America and Scandinavia and genotyped with 2974 SNP markers. Fusarium head blight ( FHB), deoxynivalenol ( DON) content, days to flowering ( DTF) and days to yellow maturity ( DTM) were scored in field trials in 2011-12. Trials with phenotypic ranges from 1 to 30 ppm, and sufficient accuracy were obtained by an augmented design and spawn inoculation. Discriminant analysis- PCA identified the different gene pools, with overlaps corresponding to known pedigrees and germplasm exchanges. Structure was negligible and GWAS (genomewide association study) was done using mixed linear models in TASSEL or partial least-squares regression ( PLSR). PLSR allows simultaneous analyses of several phenotypes (environments and/or traits) and is a promising tool for GWAS in plants and should be tested in species with sequenced genomes. FHB was associated with phenology QTLs, due to very susceptible early lines from the Midwest. Lines with consistently low DON (and early heading) were identified. Six QTLs for DON were not associated with earliness, including three QTLs reported previously. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate drought tolerance and persistence in a germplasm of smooth bromegrass and association of forage productivity with different traits. Thirty-six genotypes of smooth bromegrass were clonally propagated and evaluated under two soil moisture environments for three years (2013-2015). High genotypic variation was observed among genotypes for all the measured traits. Drought stress decreased mean values for traits related to productivity. Also, the long-term stress for three years reduced the persistence of plants. Results indicated that indirect selection based on components of forage yield, which had high heritability and high correlation with yield, would be more effective to improve drought tolerance in this germplasm. The results of principal component analysis showed that there was a negative relationship between phenological traits with the persistence-related traits and yield production. This suggests that selection for earliness may indirectly promote persistent genotypes. The results showed that some Hungarian genotypes are valuable gene sources for persistence. The most persistent genotypes from both groups (Iranian and foreign) were identified using the biplot method. These genotypes may be useful for the development of populations for future studies. [ABSTRACT FROM AUTHOR]

Copyright of Plant Breeding is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Abstract Reciprocal crosses may have significantly distinct performances regarding tuber characteristics in potato, suggesting the importance of cytoplasmic effects in this crop. The selection of parents for true potato seed breeding therefore needs to consider this potential effect when determining the direction of a cross. The aim of this research was to determine whether a broad-based true potato seed breeding population, developed at the Centro Internacional de la Papa, could be affected by cytoplasmic effects in the short-day length environments of the tropics. Two random sets of reciprocal biparental crosses were included in the first set of experiments, which were grown in two contrasting Peruvian locations. Only one out of 14 reciprocal crosses showed significantly distinct performance for tuber yield and tuber set. In the second set, only one of each of the 12 reciprocal crosses had distinct performance for vine earliness, days to flowering and flowering intensity, but four of the reciprocal crosses in the second set showed distinct pollen production. The results suggest that cytoplasmic effects in this breeding population are more important for reproductive characteristics such as pollen production than for tuber yield. This finding is not surprising because male sterility in potato results from the interaction between sensitive cytoplasm and dominant nuclear genes. [ABSTRACT FROM AUTHOR]

Chromosome 3A of wheat is known to carry earliness per se genes. To determine the number of genes and their arm location, ear emergence time under a controlled environment was investigated using ditelosomic lines and homozygous recombinant substitution lines developed between chromosome 3A homologues from ‘Timstein’ and ‘Chinese Spring’ (CS) in a CS genetic background. Because the ear emergence distribution was discontinuous and two separate modes were produced, the 86 recombinant lines could be divided into 21 lines as the early ‘Timstein’ 3A type and 65 lines as the late CS type. This agrees with the 1:3 independent segregation of two genes both located on chromosome 3A. Therefore, two hypotheses can be proposed, either CS(‘Timstein’ 3A) carries two genes and both are necessary to give early ear emergence, or one gene for early ear emergence is present on ‘Timstein’ 3A, but a suppressor is on CS 3A. The behaviour of ditelosomic 3AL and 3AS lines, with an ear emergence time identical to that of CS, suggested that one gene is located on the long arm and the other is on the short arm. [ABSTRACT FROM AUTHOR]

With 3 figures and 4 tables Abstract This study employed and compared different methods for capturing farmers' preference for common bean varieties in southern Ethiopia and tested their expressed preference using active selection of drought-tolerant genotypes. The results showed considerable variation in farmers' variety preferences, but the most important variation consistently focused on a fairly consistent set of variety traits. Different methods indicated that farmers considered earliness as the most important trait. Culinary qualities and marketability showed to be at least as important as drought tolerance. Comparing different methods in identifying farmers' preference indicated that recording farmers rating or ranking for traits in breeding may not be effective or predictive of adoption for new variety and resulting variation among farmers. Real-time participatory selection was quick, efficient and accurately revealed farmer preference. The relatively high level of coincidence of farmer selections and selections made by breeders and extensionists, combined with the relative consistent set of important traits to consider, suggest that diversity of farmers demand is not the first concern. The challenge of the common bean breeding for southern Ethiopia therefore lies in combining different mechanisms of drought tolerance with culinary attractiveness and marketability. Market in the study region shows to be fairly dynamic and as a consequence farmer preferences for grain types and colour are not static. Breeding that focuses on traditionally grown colours, shapes and sizes may therefore restrict farmers' access to novel attractive and adapted germplasm. [ABSTRACT FROM AUTHOR]

In North African oases Medicago sativa ssp. sativa is likely to have been cultivated for long time without contacts with ssp. falcata. In order (i) to verify the genetic distinctiveness of the alfalfa germplasm of the oasis and (ii) to examine their internal variation, 17 farm landraces were collected in Siwa oasis (Egypt) and studied with four Egyptian and three Italian cultivars (120 plants/population) by means of bio-agronomic characters in 2 years cultivation and SSR markers in ‘bulk’ samples. Siwa germplasm was similar to the cultivars for dry matter yield but differed for plant form, earliness and reaction to fall conditions; SSR analysis based on 31 polymorphic DNA fragments distinguished Siwa landraces from the two groups of varieties. The variation within Siwa group was of continuous type based on bio-agronomic traits; average genetic similarity was high (0.8959) and UPGMA dendrogram suggests poor isolation among the landraces, although all, except two, were uniquely fingerprinted. The use of putative ‘pure’ subspecies of high agronomic value in the alfalfa variety construction process is discussed. [ABSTRACT FROM AUTHOR]

Interspecific hybridization among species of cotton has lead to improvement in productivity, earliness, fibre quality and resistance to pests and diseases. However, wide crosses is often limited by the operation of either pre- or/and post-fertilization barriers. An investigation on pollen tube behaviour of four wild species in the pistils of Gossypium hirsutum was taken up. Pollen germination was normal in crosses involving Gossypium triphyllum and Gossypium armourianum and markedly inhibited in the crosses involving Gossypium davidsonii and Gossypium thurberi. Pollen tubes reached the pistils and fertilization was accomplished within 8 h after pollination (HAP) in control cross. Even though delay in pollen tube was a common phenomenon in all the four crosses successful fertilization was observed in crosses involving G. triphyllum and G. armourianum, as they reached the ovary at 24 HAP. In crosses with G. davidsonii and G. thurberi, pollen tubes failed to reach the ovary even at 24 HAP indicating the presence of strong stylar and ovarian incompatibility. Measures to overcome such barriers to interspecific hybridization in the incompatible crosses are discussed. [ABSTRACT FROM AUTHOR]

Presence of substantial heterosis and economic hybrid seed production are two most desirable components for success of any commercial hybrid breeding programme. Thermosensitive genic male sterile (TGMS) lines of rice, in this regard, have tremendous potential in realizing further quantum jump in yield and economical hybrid seed cost. Analyses for combining ability and heterosis over optimum (120N : 60P2O5 : 40K2O kg/ha) and high (200N : 90P2O5 : 60K2O kg/ha) fertility environments for six traits were made in 2 years (2001 and 2002) using 120 hybrids of inter- and intra-subspecific nature derived from hybridization of 30 elite indica TGMS lines and four cultivars, viz., ‘Pant Dhan 4’ and ‘Ajaya’ (I = indica), ‘Taichung 65’ (J = japonica) and ‘IR 65598-112-2’ (TJ = tropical japonica) in line × tester mating design. Predominance of non-additive genetic variance suggested good prospects of hybrid breeding. Pooled analysis revealed highly significant variances for lines, general combining ability (GCA), specific combining ability (SCA) and line x tester. TGMS line 365-8S was the best general combiner for all the six traits including grain yield. Trend of relative mid-parent heterosis for grain yield, panicle length, grain number per panicle and earliness in flowering was I/TJ > I/J > I/I. For panicle number per plant and 1000-grain weight, trends were I/TJ > I/I > I/J and I/I > I/TJ > I/J, respectively. Grain yield recorded heterosis of 49.3%, 71.9% and 92.7% for I/I, I/J and I/TJ hybrid groups respectively. Effect of environments on the hybrid performance indicated better response of hybrids at high fertilizer dose. Study suggests greater prospects of combining improved japonica and tropical japonica germplasms having wide compatible gene with indica TGMS lines for exploitation of intersubspecific heterosis. [ABSTRACT FROM AUTHOR]

The development of sprouting-resistant spring-wheat (Triticum aestivum L.) cultivars is a major breeding objective in many wheat-producing regions. Sprouting resistance is thought to be associated with delayed maturity. The primary objective of this study was to measure the reciprocal effects of selection for sprouting resistance and maturity. Two experiments were conducted over a 3-4-year period in Saskatoon, Canada. In the first experiment, two populations of hard red spring wheat were subjected to divergent selection (k = 10%) for maturity. In the second experiment, six populations derived from crosses between two sprouting-resistant, late-maturing, white-grained cultivars ('AUS1293' and 'AUS1408') and three early maturing, red-grained cultivars ('Park', 'PT516' and 'Roblin'), were subjected to divergent selection (k = 10%)for sprouting resistance. Selection for earliness reduced sprouting resistance in one population but had no effect in the second. For both populations, earlier maturity was associated with higher test weight but lower grain yield. In the second experiment. selection for increased sprouting resistance was effective, with realized heritabilities averaging 0.74. Increased sprouting resistance was associated with a slight delay (1-2.5 days) in time to spike emergence in four out of six populations, but had little effect on time to maturity in most populations. There was a trend towards redder grain in the sprouting resistant selections. The recovery of sprouting-resistant, early maturing segregants was relatively low. averaging less than 10% over the six populations. In conclusion, selection for increased sprouting resistance can result in delayed maturity, but the magnitude of that delay will vary among populations. [ABSTRACT FROM AUTHOR]

Seed production in perennial ryegrass, Lolium perenne L., is low. Early selection for high seed yield carried out in spaced plants would be valuable for breeders, but only if this potential is also expressed in derived progenies sown later in drilled plots. Therefore, spaced-plant traits assessed on clonal ramets of 31 genotypes in each of two perennial ryegrass varieties in four environments were related to seed production characteristics in drilled plots of open-pollinated progenies of these plants. Significant differences were found among these half-sib families for seed yield, thousand-grain weight, spring performance and earliness. The number of spikelets per ear in the maternal plants was negatively correlated with the seed yield of the progenies, explaining 17 % of the variation for seed yield in the cv. 'Barenza' and 14 % in the cv. 'Wendy'. Multiple regression analyses revealed that no combinations of plant traits consistently explained a major portion of the variation for seed yield of the progenies. The results indicate that in these varieties, spaced-plant data are of limited value in predicting seed production. Direct selection for seed yield in drills of progenies in later stages of the breeding programme remains the best method for obtaining varieties with sufficient seed production. [ABSTRACT FROM AUTHOR]

The mode of inheritance of fifteen induced morphological mutants in diploid wheat Triticum monococcum L. was determined. The results showed that earliness, reduced height, uniculm, liguleless branched spike, compact ear, and free-threshing habit of each of these mutants is the result of a single recessive mutation. Red awns and xantha traits are controlled by two recessive genes with duplicate and inhibitory gene interactions, respectively. Some of the early and dwarf mutants were non-allelic. One dwarf GA[SUB3]-insensitive mutant with recessive gene action may be a new source. Mutants such as early maturing, dwarf and free threshing habit may be of significance in breeding diploid wheat. [ABSTRACT FROM AUTHOR]

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Copyright of Plant Breeding is the property of Wiley-Blackwell and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Barley varieties were screened for their efficient drought enduring ability and associated characters which may be useful in breeding programmes. The characters studied were: relative water content, content of proline, chlorophyll stability index (CSI), and percentage grain loss per plant due to water stress subjected to 10 days from jointing to boot stage. Proline and chlorophyll stability index were greatly associated with drought response (r = +0.54; -0.49), flag leaf area (r = +0.69; -0.51) and, to a certain extent, with leaf number (r = -0.35 and +0.34). Among the studied 19 varieties of barley, only three (DL 192, DL 36, DL 3) showed high enduring ability, of these the former two fall in the early, and the last one in the late flowering group. Morphological architecture of DL 192 had gathering type tiller (narrow tiller angle), wider and floppy leaves and it also bears physiological characters (high proline and high relative water content, and low value of chlorophyll stability index) necessary for drought resistance. DL 3 and DL 36 had dispersing type tiller (wider tiller angle) and erect leaf with good leaf area/plant, but unit leaf area was low in DL 3 (relates with shading behaviour reducing water loss). Other relations of drought resistance are briefly discussed in the text. An appraisal of the various traits revealed that high proline content, and low CSI (biochemical characters), earliness, larger flag leaf area and fewer leaves per plant (morphological characters) were directly correlated with productivity of the cultivars under drought conditions. These characters could be used as a guideline for breeding drought resistant cultivars of barley. [ABSTRACT FROM AUTHOR]

Millets are known for their resilience and nutritional benefits and hence believed to have a promising role in ensuring food and nutritional security under changing climatic conditions. Research on millets has intensified in recent years, especially in dissecting the genetic components of yield, stress tolerance and nutritional quality traits. Recent advances in next‐generation sequencing, bioinformatics and associated statistical procedures for genome‐wide association studies (GWAS) have provided wide opportunities to resolve the genetic complexity of polygenic traits by measuring historical and evolutionary recombination events in the natural population(s). During the past decade, GWAS has been successfully employed to identify key genes controlling growth, development, stress tolerance, nutrient use efficiency and nutritional quality traits in sorghum, pearl millet, foxtail millet and finger millet. However, progress in other minor millets is still in its infancy. Genetic dissection of these complex traits in millets may pave the way for genetic alteration of climate resilience, photosynthesis and nutrient accumulation in rice and wheat. In this review, progress in GWAS analysis in detecting QTLs underlying complex traits in sorghum and other millets is highlighted. [ABSTRACT FROM AUTHOR]

Fourteen genetically diverse inbred lines comprising of four genic male sterile lines and 10 often pollinated lines as testers were crossed following 'line × tester' mating design to generate 40 F1s. These F1s, parents and check 'CH‐27' were evaluated in α‐lattice square design, replicated thrice during summer seasons of 2020 and 2021. The male sterile line DPChMS 9‐2 was good general combiner for marketable fruit yield and eight other component traits while testers namely, DPCh 10, PBC 535, VVG, Him Palam Mirch‐2 and DPCh 40 showed significant GCA for majority of yield related traits. The hybrids DPChMS 9‐2 × HPM‐2, DPChMS 9‐2 × DPCh 40, DPChMS 9‐2 × DPCh 101, DPChMS 9‐2× VVG and DPChMS 26‐1× HPM‐1 were the most desirable based on specific combining ability (SCA) and economic heterosis for fruit yield and other important traits. Heterosis was positively correlated with SCA indicating prediction of potential hybrids can be made based on both these parameters simultaneously. Present study provides an opportunity to exploit top hybrids for stability and commercial cultivation. [ABSTRACT FROM AUTHOR]

Blast disease causes serious economic yield losses in pearl millet. Identification and introgression of genomic regions associated with blast resistance can help to develop resistant cultivars to minimize yield losses incurred from blast outbreaks. In this study, 384 advanced pearl millet genotypes were screened against six blast pathotype‐isolates (major pearl millet growing agro‐ecologies of India), namely, Pg 45, Pg 118, Pg 138, Pg 186, Pg 204 and Pg 232. Analysis of variance showed significant (P <.001) variation among genotypes for blast reaction (susceptible to resistance). ICMR 08111 and ICMR 10888 genotypes showed resistance to all six blast pathotypes. A genome‐wide association study performed with 264,241 single nucleotide polymorphic markers could successfully identify 15 SNPs (P = 1.26 × 10−7 to 9.22 × 10−12) underlying the genomic regions governing blast‐resistance across five different chromosomes. The SNPs reported had a significant association in at least two of the three models tested (GLM, MLM and Farm CPU). These SNPs can be used in pearl millet‐resistant breeding programmes after their function has been validated across different genetic backgrounds. [ABSTRACT FROM AUTHOR]

A barley drought tolerance Quantitatif Trait Locus (QTL) on chromosome 2 was transferred from tolerant cultivar 'Tadmor' to susceptible 'Baronesse' and 'Aydanhanım'. Effects of this QTL on drought tolerance and other traits were studied using near‐isogenic lines under controlled environments and field trials for two years. This QTL resulted in 5.0% and 9.1% improvement in leaf relative water content of 'Baronesse' and 'Aydanhanım' cultivars, respectively, under controlled environments. The QTL accelerated heading and maturity by 2.5 days in 'Baronesse' and by 5–6 days in 'Aydanhanım'. It was associated with shorter stature and more ears. This QTL region increased grain yields by 1.1 and 0.6 t/ha in 'Baronesse' and 'Aydanhanım', respectively, mainly by increasing the number of tillers. There were previous reports related to yield promoting effects of this region harbouring flowering locus eps2 (barley HvCEN gene). However, sequencing of 1025 bp fragment encompassing HvCEN coding region revealed that our parents and near‐isogenic lines had no Single Nucleotide Polymorphism (SNP) variation, ruling out direct involvement of eps2. These findings pointed to the possible effect of another flowering locus in the QTL region. [ABSTRACT FROM AUTHOR]

Cotton leaf curl disease (CLCuD) is a major threat to cotton production in Asia and Africa. Using marker‐assisted breeding can be the best sustainable approach to tackle CLCuD. Identification of new QTLs in the indigenous cotton germplasm is necessary to combat CLCuD. The current study was designed to construct a genetic linkage map of bi‐parental F2:F3 populations developed from highly tolerant MNH‐886 and highly susceptible S‐12 cotton cultivars. One hundred seven CLCuD‐associated simple sequence repeat (SSR) marker alleles were identified as polymorphic and three new QTLs were found on chromosomes C11, C19 and C21. Two QTLs on chromosomes C11 and C19 were detected in both F2 and F3 populations in the region flanked by SSR markers CIR316 and BNL4094, and BNL285 and BNL3348, respectively. Whereas, one QTL on chromosome C21 was detected in the region flanked by SSR markers JESPR158 and JESPR135 in both F2 and F3 generations. The CLCuD‐associated QTLs identified in this study can help fine‐tune the molecular mapping of the QTLs on the cotton genome against CLCuD. [ABSTRACT FROM AUTHOR]

A set of simple sequence repeat (SSR or microsatellite) markers was used to discriminate a collection of 33 Spinacia oleracea hybrid cultivars from seven different breeding stations all over the world. All SSR markers were genic microsatellite markers located in coding or non-coding regions of genes of known function. Cluster analysis based on 13 of the SSR markers showed that the spinach hybrids grouped into three clusters. The first two clusters consisted of European spinach types, which were well discriminated according to their origin from different breeding stations. The third cluster was a mixture of Asian as well as European types of spinach. Subclusters in this group did not reflect differences in morphology, earliness or company origin. The data show that genic microsatellites are a powerful tool for discrimination of spinach cultivars. [ABSTRACT FROM AUTHOR]

Deploying maize varieties with fall armyworm (Spodoptera frugiperda [J.E. Smith]; FAW) resistance, desirable product profiles (PPs) and climate resilience is fundamental for food and economic security in sub‐Saharan Africa (SSA). This study reviewed and identified challenges and opportunities for effective and accelerated breeding of demand‐led maize hybrids with FAW resistance and adaptation to the diverse agro‐ecologies of SSA. Lessons were drawn on improving breeding efficiency through adequate genetic variation delivered via prebreeding programmes, speed breeding and a reduced breeding stage plan. Appropriate PPs aligned with demand‐led breeding approaches were highlighted as foundations for variety design and commercialization. Challenges to accelerated FAW resistance breeding in maize included inadequate funds and modern tools; poor adaptation of some exotic donor parental lines; lack of information on FAW resistance among local varieties; lack of integration of molecular markers associated with FAW resistance and agronomic traits into selection plans; and limited infrastructure for FAW rearing and germplasm screening. Integration of modern breeding tools and scientific innovations were recommended for accelerated development and release of FAW resistant and market‐preferred maize varieties. [ABSTRACT FROM AUTHOR]