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Castor is an important oilseed crop grown in India. However, its cultivation is seriously affected by several diseases, e.g. wilt disease caused by Fusariumoxysporum f. sp. ricini being economically relevant. Host plant resistance is the best option for the management of this disease. A total of 524 castor genotypes were screened against wilt disease under sick plot conditions for five years from 2013–2014 to 2017–2018. The wilt sick plot was maintained with a inoculum load of 2 × 103 CFU/gm of soil and the genotypes were screened alongside resistant (48–1) and susceptible (JI-35) cultivars. It was observed that 109 castor genotypes were susceptible to wilt with more than 50% wilt incidence whereas, 32 genotypes; i.e., DCS-86, DCS-118, DCS-108, DCS-105, DCS-107, DPC-17, DPC-18, DPC-21, DPC-23, DPC-24, DPC-25, M-571, DPC-28, PMC-9, PMC-11, PMC-14, PMC-15, PMC-16, PMC-17, PMC-24, PMC-38, PMC-55, PMC-60, PVT- 11–3, PVT-11–18, PVT-11–17, PVT-11–21, PVT-12–4, PVT-12–6, PVT-12–72 and PVT-11–26 recorded < 20% wilt incidence during the consecutive years of testing. Three wilt-resistant parental lines of castor IPC-21/DPC-21(INGR No.21107), M-571 (INGR No. 21230), and ICS-200 (INGR No. 21157) were identified and registered by the Plant Germplasm Registration Committee. Among the screened parental lines, PMC-14 showed a resistant reaction of 10–16.7% to wilt for three years and was used as a parent ICS-164 (PMC-14) in developing wilt-resistant hybrid ICH-66, which was released for cultivation in five states of India, namely, Andhra Pradesh, Telangana, Tamil Nadu, Karnataka and Odisha. The resistant lines identified in this study could be used for breeding wilt-resistant castor hybrids. [ABSTRACT FROM AUTHOR]

The structure and physicochemical properties of starch were important factors to determine the quality of foxtail millet. While hybrid foxtail millet has made greater progress in yield, it has made slower progress in quality than conventional foxtail millet with a more complex genetic base, which was jointly influenced by the parents. However, there were no reports on the comparison of the starch structure and physicochemical properties of hybrid foxtail millets and their parents. In this study, the amylose content, morphology structure, granule size distribution, X-ray diffraction, short-range ordered structure, pasting properties, and thermal characteristics of starches derived from Changzagu 466 (466), Changzagu 333 (333), Changzagu 2922 (2922) and their parent materials were analyzed. The results showed that compared with male parents, the starches from three hybrid foxtail millets and their female parents had larger average particle size, d(0.1), d(0.5), and gelatinization enthalpy (ΔH), while the amylose content values of three hybrid foxtail millets were 26.0%, 28.8%, and 28.9%, which were between the parents (25.8~27.1%, 25.4~28.8%, and 23.6~29.5%), with conclusion temperature (Tc) being higher than the parents and having a lower breakdown viscosity. The peak viscosity of Changzagu 466 (466) and Changzagu 2922 (2922) was 5235.5 cP and 5190.8 cP, respectively, lower than that of their parents (5321.0~6006.0 cP and 5257.0~5580.7 cP), while the peak viscosity of Changzagu 333 (333) was 5473.8 cP, falling between the parental values (5337.5~5639.5 cP). The cluster analysis results showed that the starch structure and physicochemical properties of hybrid foxtail millet were significantly different from those of female parents, which were mainly influenced by male parents. The findings of this study will establish a theoretical foundation for the enhancement and innovation of high-quality foxtail millet germplasm resources, as well as the development of high-quality hybrid foxtail millet combinations. [ABSTRACT FROM AUTHOR]

The structure and physicochemical properties of starch were important factors to determine the quality of foxtail millet. While hybrid foxtail millet has made greater progress in yield, it has made slower progress in quality than conventional foxtail millet with a more complex genetic base, which was jointly influenced by the parents. However, there were no reports on the comparison of the starch structure and physicochemical properties of hybrid foxtail millets and their parents. In this study, the amylose content, morphology structure, granule size distribution, X-ray diffraction, short-range ordered structure, pasting properties, and thermal characteristics of starches derived from Changzagu 466 (466), Changzagu 333 (333), Changzagu 2922 (2922) and their parent materials were analyzed. The results showed that compared with male parents, the starches from three hybrid foxtail millets and their female parents had larger average particle size, d(0.1), d(0.5), and gelatinization enthalpy (ΔH), while the amylose content values of three hybrid foxtail millets were 26.0%, 28.8%, and 28.9%, which were between the parents (25.8~27.1%, 25.4~28.8%, and 23.6~29.5%), with conclusion temperature (Tc) being higher than the parents and having a lower breakdown viscosity. The peak viscosity of Changzagu 466 (466) and Changzagu 2922 (2922) was 5235.5 cP and 5190.8 cP, respectively, lower than that of their parents (5321.0~6006.0 cP and 5257.0~5580.7 cP), while the peak viscosity of Changzagu 333 (333) was 5473.8 cP, falling between the parental values (5337.5~5639.5 cP). The cluster analysis results showed that the starch structure and physicochemical properties of hybrid foxtail millet were significantly different from those of female parents, which were mainly influenced by male parents. The findings of this study will establish a theoretical foundation for the enhancement and innovation of high-quality foxtail millet germplasm resources, as well as the development of high-quality hybrid foxtail millet combinations.

Inter‐sub‐specific hybridization between indica and tropical japonica rice germplasm is the most efficient approach for broadening the genetic base of hybrid rice parental lines and enhancing the heterotic potential of hybrids in a tropical country like India. In the present study, 106 indica/tropical–japonica derived lines were developed through inter‐sub‐specific hybridization and screened using functional markers with respect to the major fertility restorer genes, Rf3 and Rf4, and the wide compatibility gene, S5n. The fertility restoration ability of newly developed restorers was validated through test cross nursery performance. The functional markers were observed to accurately predict the trait of fertility restoration. From the present study, the decreasing order of efficiency of different gene combinations on fertility restoration ability are as follows: Rf4/S5n > Rf4/Rf3/S5n > Rf4 > Rf4/Rf3 > Rf3/S5n > Rf3. Based on multi‐trait stability index (MTSI) analysis, the four newly identified restorers, that is, RP6388‐90, RP6382‐49, RP6375‐81 and RP6368‐38, were selected as the top best performing genotypes with high stability for multiple traits, and these genotypes will be useful for the development of superior rice hybrids in India. [ABSTRACT FROM AUTHOR]

Relevance. Downy mildew (Pseudoperonospora cubensis) is a serious problem when growing cucumber both in open and protected ground. One of the most effective methods of combating Pseudoperonospora cubensis is the cultivation of genetically resistant hybrids. To create them, it is necessary to include genetic markers in breeding work that speed up and increase the accuracy of selection. The F311 genetic marker of the SGR gene provides resistance to the destruction of chlorophyll, which can significantly reduce the rate of development of downy mildew, as well as preserve the growth and development of plants.Material and methods. In 2021-2022, at the Crimean Breeding Center, parental lines of cucumbers were studied in spring rotation in open ground. A total of 39 samples were studied. Their resistance to downy mildew against a natural infectious background was assessed on a 5-point scale. Hybrids were chosen as standards: St resistance – Phoenix+, St susceptibility – F1 Tchaikovsky, which scored the maximum damage score during visual assessment, All studied material was tested for the presence of the SGR gene for resistance to chlorophyll destruction using PCR analysis using the F311 marker.Results. The operating efficiency of the F311 (SGR) marker under the conditions of this experiment was 87.2%. And the efficiency of using the F311 (SGR) marker for assessing resistance to Pseudoperonospora cubensis is 84.6%. Based on the results of the experiment, we can conclude that the use of the F311 (SGR) marker will significantly speed up the process of selection and creation of hybrids resistant to Pseudoperonospora cubensis with a complex of economically valuable traits.

Sunflower production in the world is expending towards marginal areas, along with rapid changes in cultural practises like no-till planting and weed management. The frequency and severity of abiotic constraints also rise as a result of climate change. Helianthus annuus is well-known for its adaptability to a wide range of agronomic conditions, by its robust root system that is capable of absobing water from deeper soils. However, water stress lowers grain yields and fatty acid content with complex phenotypic, physiological and biochemical signs. In this study which was carried out to develop parental lines tolerant or high-tolerant to drought, physiological screenings were carried out on 8 sunflower genotypes. Genotypes were planted in pots in a greenhouse and grown at three different irrigation levels (I100, I66 and I33). The genotypes were watered together until they reached the 6-8 leaf stage. Then, each genotype was managed and irrigated solely. Number of days between sowing and floweing days, number of days between sowing and number of days between sowing and number of days to transfer the embryo to the nutrient medium, plant height, head diameter, number of seeds in the head was between 52-67 days; 65-80 days; 50-200 cm; 3.0-13.0 cm; 25-500 pieces, respectively. Plant weight, plant high, root length, number of leaf, nnmber of days from transplant to glasshouse, number of days from transplant to field was between 0.22-0.45 g; 2.09-4.62 cm; 1.70-5.27 cm; 3.60-5.87 pieces; 5 or 6 days; 10-12 days, respectively. In the experiments, it was found that two and a half generations could be achieved in one year. The genotypes K26-33 and K78-100 are located closest to the center as the most ideal genotypes in terms of the examined characteristics. In the MS environment, in terms of the characteristics examined, the genotypes K105-100, K78-100, K105-66, K26-100 and K1-100 were the preferred genotypes as they are located close to the center. [ABSTRACT FROM AUTHOR]

Relevance. Cucumber green mottled mosaic virus (CGMMV) is a highly specialized virus (group Tobamovirus). It is a significant threat to cucurbits. On a high infectious background, cucumber yield losses, both in open and protected ground, can be close to 100%. The spread of the virus occurs in many ways. The most dangerous is the infected seed material. One of the effective methods of preventing CGMMV is the creation of genetically resistant hybrids to viral diseases. An experiment was conducted to determine the effectiveness of the use of the marker F295 for the selection of resistant samples.Results. When comparing the results of determining resistance against an artificial background and the results of PCR analysis for the same samples, we calculated the efficiency of the genetic marker F295, which was 65%. Since the level of effectiveness is average, for a more objective assessment, it is necessary to create another – the main marker, which will determine the direct presence of resistance to CGMMV. The use of the F295 marker is relevant in combination with other methods for deter[1]mining resistance, which will speed up and increase the efficiency of the breeding process.

The experimental trial was conducted at Sorghum Research Centre, Marathwada Agricultural University, Parbhani during kharif 2021 in randomized design with 3 replications. Eighteen parental (B & R) lines were evaluated to study genetic diversities and variability for fifteen yield contributing characters. Among all the eighteen genotypes of parental lines significant differences were observed for yield and its yield contributing traits except total chlorophyll content. Coefficient of variance at phenotypic level showed higher values than at genotypic level among all traits. Coefficient of variance for the traits like chlorophyll stability index (G=23.035, P=23.714), leaf area (G=21.064, P=21.673), 1000 grain weight (G=28.845, P=29.929), fodder yield (G=21.858, P=22.458), grain number per panicle (G=29.564, P=30.158), leaf dry weight (G=29.044, P=29.903) was observed high at both level. Traits like plant height (H=90, GAM=21.041), grain yield (H=86, GAM=29.074), leaf dry weight (H=94, GAM=23.664), leaf area (H=94, GAM=42.17), chlorophyll stability index (H=94, GAM=46.093), grain number per panicle (H=96, GAM=59.703), fodder yield (H=94, GAM=43.823),1000 grain weight (H=92, GAM=52.270) and harvest index (H=84, GAM=32.321) were recorded high heritability with high genetic advancement. Genotype AKR 504, NR 39-15, KR 218, KR 219, PMS 100B, AKMS 90 B and INDORE 12 showed the better performance for all characters thus, should be used for development of hybrids and inbreds in breeding programmes by DUS (Distinctness, Uniformity and Stability) testing. [ABSTRACT FROM AUTHOR]

The knowledge of genetic variability, combining capability, and gene activity are vital in enhancing wheat productivity. Six diverse wheat genotypes, Anmol91, Fatehjung16, Khattakwal, Auqab2000, PR128, Abaseen 2021, and KT06, crossed with three strip rust-resistant wheat lines, i.e., YR5, YR10, and YR15, employed line × tester hybridization. The analysis determined that the general combining ability (GCA) and specific combining ability (SCA) variances were significantly different for examined parameters (p < 0.05). Parental lines Auqab2000 and Fatehjung16 emerged as better general combiners for earliness and yield-related attributes; however, Auqab2000 × YR5, KT06 × YR5, Khattakwal × YR10, PR128 × YR5, Khattakwal × Auqab, and KT06 × YR10, proved the top particular cross combinations for contributing features of grain yield per plant. Results also showed that lines import sufficient variety to manifest the traits under investigation. For almost all tested qualities, the value of σ²gca/σ²sca demonstrated a non-additive gene effect, except for days to maturity, which the additive gene action influenced. The selection of superior plants should take time until later segregation generation when non-additive gene activities dominate. The genotypes chosen for the current study are crucial genetic resources for wheat's continued gene development. [ABSTRACT FROM AUTHOR]

The experimental trial was conducted at Sorghum Research Centre, Marathwada Agricultural University, Parbhani during kharif 2021 in randomized design with 3 replications. Eighteen parental (B & R) lines were evaluated to study genetic diversities and variability for fifteen yield contributing characters. Among all the eighteen genotypes of parental lines significant differences were observed for yield and its yield contributing traits except total chlorophyll content. Coefficient of variance at phenotypic level showed higher values than at genotypic level among all traits. Coefficient of variance for the traits like chlorophyll stability index (G=23.035, P=23.714), leaf area (G=21.064, P=21.673), 1000 grain weight (G=28.845, P=29.929), fodder yield (G=21.858, P=22.458), grain number per panicle (G=29.564, P=30.158), leaf dry weight (G=29.044, P=29.903) was observed high at both level. Traits like plant height (H=90, GAM=21.041), grain yield (H=86, GAM=29.074), leaf dry weight (H=94, GAM=23.664), leaf area (H=94, GAM=42.17), chlorophyll stability index (H=94, GAM=46.093), grain number per panicle (H=96, GAM=59.703), fodder yield (H=94, GAM=43.823),1000 grain weight (H=92, GAM=52.270) and harvest index (H=84, GAM=32.321) were recorded high heritability with high genetic advancement. Genotype AKR 504, NR 39-15, KR 218, KR 219, PMS 100B, AKMS 90 B and INDORE 12 showed the better performance for all characters thus, should be used for development of hybrids and inbreds in breeding programmes by DUS (Distinctness, Uniformity and Stability) testing.

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The field and laboratory experiments were conducted at ZARS, V. C. Farm, Mandya, during kharif 2020 to study the phenology of parental lines of promising maize hybrids for their seed production potentiality. The results revealed that mean sum of squares due to parental lines indicated significant differences for growth and yield parameters viz., field emergence, plant height, cob length, cob weight, number of rows per cob, number kernels per row and seed yield per hectare and quality parameters viz., hundred seed weight, seed germination, mean seedling length and seedling vigour index I and II. Among the parental lines MAI-729 has showed significantly higher cob weight (114.33 g), hundred seed weight (29.11 g), seed yield per hectare (45.71 q ha-1) and seed vigour index-I and II (3550 and 7673, respectively). Therefore, MAI-729 line could be recommended for breeding and seed production programmes. [ABSTRACT FROM AUTHOR]

Sorghum in Mexico ranks third in grain production. This study aimed to estimate general combining ability (GCA) and specific combining ability (SCA) for commercial and experimental sorghum grain parents and hybrids. The combining ability was estimated using the line x tester method described by Kempthorne. The experiment was established during the spring-summer 2018 cycle at INIFAP, Las Huastecas, México. It consisted of five lines, eight testers and 40 hybrids; in a randomized block design with three replications. The ANOVA showed highly significant differences for lines, testers, and line x testers, suggesting the existence of a broad base of genetic variability. GCA and SCA differences were statistically significant for grain yield, specific grain weight and plant height, indicating additive gene relevance, dominance and epistasis. For grain yield, the experimental lines: RB214A, RB225A and RB248A, and the testers RB133 and RB221, resulted significantly higher in GCA and superior to commercial RB225A line and RTx430 and RTx437 testers. Seventeen experimental hybrids were found to have significantly higher in SCA and were superior to INIFAP commercial hybrids. Highlights • The combining ability was estimated using the line x tester method in grain sorghum; General Combining Ability (GCA) and Specific Combining Ability (SCA) were important for grain yield, grain specific weight and plant height. • GCA and SCA differences were statistically significant for grain yield, specific grain weight and plant height, in grain sorghum, indicating additive gene relevance, dominance and epistasis.

Sorghum in Mexico ranks third in grain production. This study aimed to estimate general combining ability (GCA) and specific combining ability (SCA) for commercial and experimental sorghum grain parents and hybrids. The combining ability was estimated using the line x tester method described by Kempthorne. The experiment was established during the spring-summer 2018 cycle at INIFAP, Las Huastecas, México. It consisted of five lines, eight testers and 40 hybrids; in a randomized block design with three replications. The ANOVA showed highly significant differences for lines, testers, and line x testers, suggesting the existence of a broad base of genetic variability. GCA and SCA differences were statistically significant for grain yield, specific grain weight and plant height, indicating additive gene relevance, dominance and epistasis. For grain yield, the experimental lines: RB214A, RB225A and RB248A, and the testers RB133 and RB221, resulted significantly higher in GCA and superior to commercial RB225A line and RTx430 and RTx437 testers. Seventeen experimental hybrids were found to have significantly higher in SCA and were superior to INIFAP commercial hybrids. [ABSTRACT FROM AUTHOR]

The present investigation aimed to assess the nature and magnitude of genetic divergence available in the Hybridization Block (E1) and National Hybridization Garden (E2) of ICAR-Sugarcane Breeding Institute, Coimbatore and to select the suitable diverse genotypes as parents for further utilization. Principal component and hierarchical cluster analyses were carried out in sixty eight genotypes with nine traits. In E1, the first three principal components explained about 73.45 per cent of the total variability and remaining six components accounted 26.55 per cent of variability. The PC 1 explained a maximum variability of 44.85 per cent followed by PC 2 and PC3. In E2, the first three principal components explained about 76.71 per cent of the total variability among the genotypes and the remaining six components described 23.29 per cent towards the total diversity. Nineteen clones viz., Co 0314, Co 8371, Co 85019, Co 86010, Co 94008, Co 98010, Co 11015, Co 12014, Co 14002, CoSnk 05103, CoV 89101, CoV 92103, CoC 671, CoT 8201 Co 1148, CoH 119, SP 80-185, ISH 100 and ISH 2 were found promising in both the environments indicating their potential to perform under varied ecological situations. Twenty clones in E1 and 38 clones in E2 can be further exploited as trait specific donors and the traits cane height, cane diameter, cane weight should be given more emphasis for further selection.

Perfect synchronization between the parental lines of Sahyadri rice hybrid viz., IR 58025A (A-line), IR 58025B (B-line) and KJTR-3 (R-line) were determined by using three methods viz., Growth duration difference, (GDD) Leaf number difference (LND) and Effective accumulated temperature (EAT). The seeding interval between A x B line was 2.66 days and between A x R was 11.89 days. The B line flowered 2.66 days before A line and R line flowered 11.89 days after A line. The Effective Accumulated temperatures (EAT) for attaining 50% flowering of A, B, & R line were 2265.91ºC, 2189.61 ºC and 2596.29 ºC respectively. The difference of EAT between A and B lines was 76.30 ºC and between A and R lines was 330.38ºC. Parental lines viz., A, B, and R lines flowered after 13.60, 12.60 and 16.70 leaves respectively. The leaf number difference between A and B lines was 1.0 leaf and between A & R line 3.2 leaves. The perfect synchronization of flowering between A and B lines can be achieved by sowing A line 3 days before second date of seeding of B line, sowing of B line after emergence of 1.0 leaf of A line and when A line reaches its EAT to 76.30 ºC. Similarly, the synchronization of flowering between A and R line can be achieved by sowing A line 12 days after second date of seeding of R line, after emergence of 3.2 leaves of R line and when R line reaches its EAT to 330.38ºC. This phenology model can be exploited for perfect synchronization of flowering in commercial seed production of A x B line and A x R line of Sahyadri rice hybrid.

The paper describes the potato parental line breeding programme developed in Poland from the 1960s. The aim of the programme was to create parental forms useful for speeding up the breeding of new potato varieties and getting higher efficiency in directed selection for desired traits. The programme introduced new sources of resistance and quality traits into the Polish breeding pool by conducting research and breeding of tetraploid and diploid parental lines. The programme had significant impact on potato breeding, with 72 Polish potato varieties originating from crossings involving parental lines. These varieties show higher levels of resistance to major pathogens of potato crops, including resistance to Potato virus Y and late blight in starch group. Besides the direct impact on potato breeding, the programme was the stimulus for developing studies focused on potato genotype. [ABSTRACT FROM AUTHOR]

Maize is the Queen of Cereals and has proven its utility as food, feed, fodder, fuel and raw materials for many industries. In order to meet the ever increasing demand of maize, the hybrid seed production plays an important role. The hybrid performance is based on its parental inbred potential and longevity. Accelerated ageing test is an efficient method to measure the seed vigour and to predict seed longevity. Single cross maize hybrids viz., CoH(M) 6, CoH(M) 8 and their parental lines viz., UMI 1200 (female parent of CoH(M) 6), UMI 1201 (female parent of CoH(M) 8) and UMI 1230 (common male parent of CoH(M) 6 and CoH(M) 8) were subjected to accelerated ageing test at 40 ± ْ 1 C and 100 per cent relative humidity for a period of 10 days. The results of the study revealed that the hybrid seeds of CoH(M) 6 maintained their viability for a longer period up to four days when compared to CoH(M) 8 which maintaining its viability up to third day of accelerated ageing as per Indian Minimum Seed Certification Standard (90 per cent germination). All the inbreds lost their viability after the first day of accelerated ageing and the rate of deterioration was higher in UMI 1230. The other parameters like seedling length (cm), dry matter production (g/10 seedlings) and vigour index decreased upon ageing and electrical conductivity (dsm-1) increased with increase in accelerated ageing periods.

In this study, by analyzing the relationship between hybrid combinations and parental lines, we found that the eating quality traits of hybrid combinations were determined by both parents. The sterile lines determined the overall eating quality characteristics of the hybrid combinations. For the same sterile line, there were some correlations between the hybrid combinations and restorer lines in terms of taste value, rapid visco analyzer breakdown and setback values, apparent amylose content, and cooked rice hardness and stickiness. Analysis of the starch fine structure between hybrid combinations and their restorer lines demonstrated positive correlations between them in terms of short-branch amylopectin chains and amylose. Moreover, different allelic combinations of the Wx gene showed different genetic effects on the eating quality traits of hybrid rice. Overall, this study provides a framework for the development of hybrid rice with superior eating quality.

In field experiments conducted in 2019-2020, two new maize hybrids - Kn 317 and Kn 649 and one experimental promising hybrid - Kn 321 were studied. In each of the hybrids, its parent components were studied together with F1, ie. . P1, P2, F1. The hybrids Kn 317 and Kn 321 are from the early FAO group (group 300) and Kn 649 - from the late FAO group (group 600). The aim of the present study was to determine the specific heterosis manifestations and the dominance in F1 of important quantitative traits for selection: plant height, number of leaves, photosynthetic pigments, leaf area, cob length, grain weight and yield per acre. The nature of inheritance of quantitative traits has been established. The results show that in terms of plant height the late hybrid Kn 649 (MPH 47.99%, BPH-40.80%) is more heterosis, and for the area of the pinched leaf - Kn 321 (MPH-41.14%, BPH-21.66%). In the signs associated with photosynthetic activity, there are less pronounced heterosis manifestations affecting the number of photosynthetic leaves and photosynthetic pigments. An exception is the higher heterosis for the second trait, in which higher values were found for Kn 649 (MPH-39.12%, BPH-20.34%). In the structural elements of yield - cob length and grain weight, higher heterosis was found in hybrid Kn 321 for the first trait and also higher in Kn 317 for the second trait. Highly heterozygous manifestations were found for grain yield in hybrid Kn 317, followed by Kn 649 and Kn 321. According to the degree of dominance in F1, heterosis affecting the studied traits is due to positive overdominance for the studied hybrids. [ABSTRACT FROM AUTHOR]

Knowledge of genetic diversity and potential heterotic relationships among parental lines is of significant importance in hybrid rice breeding programs. In the present study, in order to understand the genetic diversity among 96 parental lines, they were characterized for their diversity with respect to their morphological traits (n = 12) and molecular markers using a set of 50 SSR markers. Morphological diversity was estimated using Mahalanobis D2 statistics in terms of generalized group distance. Based on morphological diversity analysis, the 96 lines were grouped into 5 major and 13 monogenotypic clusters. In molecular marker analysis, the parental lines were consistently clustered into B (Maintainer group) and R (Restorer group) groups based on distance and model based approaches. Strong correspondence was observed between the pedigree of parental lines with molecular genotyping based grouping than morphological trait based grouping. From the results of the present investigation, it is evident that the available diversity among the two groups i.e., maintainer group (B) and restorer group (R) is sufficient for developing heterotic hybrids, but within the maintainer and restorer groups, the diversity is limited, the diversity among restorers was moderate, while it was low among the maintainers and hence efforts are needed for broadening their genetic base of parental lines for development and adoption of high-yielding hybrids. [ABSTRACT FROM AUTHOR]

Hollow heart, a physiological disorder, impacts tuber quality and make marketable tubers unattractive and can have adverse effect on marketability of the produce. The investigation on one hundred eight(108) potato genotypes for presence of hollow heart symptoms revealed that 77 genotypes (71%) were free from hollow heart symptoms, while remaining 31 genotypes (29%) showed presence of 10-100% hollow heart symptoms. Most of the indigenous varieties and advanced clones were free from hollow heart symptoms. Screening of 5-10 medium sized tubers (80-100 gram) per genotype depending upon availability of tubers in initial or advanced clonal stages would be realistic approach for screening of hollow heart in potatoes. Parental line selected for hybridization in potato breeding must be free of hollow heart to achieve the desirable gain in the segregating population. [ABSTRACT FROM AUTHOR]

(1) Background: Although resistance to pathogens and pests has been researched in many potato cultivars and breeding lines with DNA markers, there is scarce evidence as to the efficiency of the marker-assisted selection (MAS) for these traits when applied at the early stages of breeding. A goal of this study was to estimate the potential of affordable DNA markers to track resistance genes that are effective against the pathogen Phytophthora infestans (Rpi genes), as a practical breeding tool on a progeny of 68 clones derived from a cross between the cultivar Sudarynya and the hybrid 13/11-09. (2) Methods: this population was studied for four years to elucidate the distribution of late blight (LB) resistance and other agronomical desirable or simple to phenotype traits such as tuber and flower pigmentation, yield capacity and structure. LB resistance was phenotypically evaluated following natural and artificial infection and the presence/absence of nine Rpi genes was assessed with 11 sequence-characterized amplified region (SCAR) markers. To validate this analysis, the profile of Rpi genes in the 13/11-09 parent was established using diagnostic resistance gene enrichment sequencing (dRenSeq) as a gold standard. (3) Results: at the early stages of a breeding program, when screening the segregation of F1 offspring, MAS can halve the workload and selected SCAR markers for Rpi genes provide useful tools.

The texture of boiled potato tubers is one of the most important quality traits. The variation of tuber texture is usually examined in relationship with dry matter or starch content. The objective of the work was to examine variation and stability of texture and starch content in tubers grown in various environments. Both traits were evaluated for the set of potato breeding lines and 10 table potato cultivars. The lines were developed in the program of parental lines carried out in Młochów Research Center, Poland. The environments were represented by three locations, which differed in cultivation system as well as climatic and soil conditions. The traits were influenced by the effects of genotype, location and their interactions. The effect of location on texture was not explained by the changes in starch content. The calculated stability parameters indicated that unstable expression of both traits was more pronounced and more frequent in breeding lines than in the cultivars. The short period of selection used in the development of the parental lines is not conducive to select potato genotypes with stable expression of quality traits. The starch content was at most moderately related with various characteristics of tuber texture.

Quantitative assessment of genetic divergence in 47 pigeonpea genotypes (22 B-lines and 25 R-lines) with respect to seed yield and yield components clustered them into 10 different groups. Among the ten clusters, cluster I was the largest comprising of 35 genotypes, representing collections from Andhra Pradesh, Karnataka and Bihar, while the clusters IV, V, VI, VII, VIII and X comprised of one genotype each. The distribution pattern of genotypes into different clusters revealed no parallelism between genetic and geographic diversity. An analysis of inter-cluster D2 values revealed higher divergence between cluster VIII and cluster IX, followed by cluster IX and X indicated that hybridization between parents selected from these clusters may result in maximum heterosis. Further, the results on cluster means revealed that there was no cluster with at least one genotype with all the desirable traits, indicating the need for judicious combination of all the targeted traits required hybridization between the selected genotypes from divergent clusters. In addition, number of seeds per pod, 100 seed weight, plant height, days to maturity and seed yield per plant together contributed for about 81.31 per cent of the total divergence and hence these traits to be emphasized during selection.

The purpose of this study is to establish the rapid discrimination system of cybrid callus lines by Fourier transform infrared (FT-IR) spectroscopy without genetic fingerprinting analysis. Genomic DNA isolated from two parental lines (Brassica oleracea var. capitata and Raphanus sativus L.) and their cybrid callus lines were analyzed by FT-IR spectroscopy in the spectral region from 4000 to 400 cm−1. Several spectral differences between the two parental lines were detected in the frequency regions of N-H stretching (amide I), C=O stretching vibrations (amide II), and PO2− ionized asymmetric and symmetric stretching. Principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were used to discriminate cybrid cell lines from the two parental species at the genomic DNA level. PLS-DA analysis provided more clear discrimination between the two parental lines and their progeny cybrid lines in the score plot. PCA loading values also showed that obvious spectral differences played a significant role in discrimination between the two parental lines and their cybrid lines. These spectral differences might be directly related to subtle changes in the base functional groups and backbone structures of genomic DNA. Considering these results, this technique could provide a research foundation for the FT-IR spectral-based diagnosis, selection, and discrimination of parental lines and their cybrids. Furthermore, this technique could be applied in the hybrid seed industry for rapid screening with high heterogeneity. [ABSTRACT FROM AUTHOR]

To understand the methylation level and genetic delivery from parental line to their hybrid in soybean (Glycine max (L.) Merr.), four groups of parental lines and their hybrids were analyzed using methylation sensitive amplification polymorphism (MSAP). Comparisons of the different methylation distributions revealed. (1) The methylation level of the whole hybrid was lower than that of the corresponding parent lines, and the internal cytosine-methylation pattern was dominant. (2) In this study, comparing the total methylation levels in hybrids and the midparent values we assume that the larger differences in DNA methylation between parental lines lead to stronger heterosis. (3) Four demethylated and one hyper-methylated fragments were sequenced and located in the reference genome by blast analysis. These methylation changes could cause expression levels changes of a protein kinase, zinc finger protein and a mitochondrial transcript, which would affect a variety of metabolic pathways in soybean, providing an explanation for the observed heterosis. [ABSTRACT FROM AUTHOR]

Hybridity and the genuineness of hybrids are prominent characteristics for quality control of seeds and thereby for varietal improvement. In the current study, the cross between two local barley genotypes (Ardhaoui: female; Testour: male) previously identified as susceptible/tolerant to salt stress in Tunisia was achieved. The hybrid genetic purity of the generated F putative hybrids and the fingerprinting of the parents along with their offspring were assessed using a set of 17 nuclear SSR markers. Among the analyzed loci, 11 nSSR were shown polymorphic among the parents and their offspring. Based on the applied 11 polymorphic SSR loci, a total of 28 alleles were detected with an average of 2.54 alleles per locus. The locus HVM33 presented the highest number of alleles. The highest polymorphism information content value was detected for the locus HVM33 (0.6713) whereas the lowest PIC value (0.368) was revealed by the loci BMAC0156, EBMAC0970 and BMAG0013 with a mean value of 0.4619. The probabilities of identical genotypes PI for the 11 microsatellite markers were 8.63 × 10. Banding patterns among parents and hybrids showed polymorphic fragments. The 11 SSR loci had produced unique fingerprints for each analyzed genotype and segregate between the two parental lines and their four hybrids. Parentage analysis confirms the hybrid purity of the four analyzed genotypes. Six Tunisian barley accessions were used as an outgroup in the multivariate analysis to confirm the efficiency of the employed 11 nSSR markers in genetic differentiation among various barley germplasms. Thus, neighbor joining and factorial analysis revealed clearly the discrimination among the parental lines, the four hybrids and the outgroup accessions. Out of the detected polymorphic 11 nuclear SSR markers, a set of five markers ( HVM33, WMC1E8, BMAC0154, BMAC0040 and BMAG0007) were shown to be sufficient and informative enough to discriminate among the six genotypes representing the two parental lines and the four hybrids from each others. These five nSSR markers presented the highest number of alleles per locus ( A), expected heterozygosity ( H), PIC values and the lowest probabilities of identity (PI). These nSSR loci may be used as referral SSR markers for unambiguous discrimination and genetic purity assessment in barley breeding programs. [ABSTRACT FROM AUTHOR]

Twenty genotypes of wheat resulting from different crossings between some wheat parental lines were compared for salt stress (control and gradually increasing salinity). Ion content in root, shoot, and flag leaves and also the root and shoot dry weights were measured. Based on these results, eight genotypes among the twenty were selected as susceptible, semi-tolerant, and tolerant genotypes for evaluating their biochemical characteristics. Results indicated that concentration of sodium (Na+) and potassium (K+) in shoot, root, and flag leaves of stressed plants were, respectively, higher and lower than that in the non-stressed plants. Overall, salinity stress caused reductions in root and shoot dry weights and relative water content (RWC), but enhancement in pigments content. Concentrations of the total carbohydrate, total protein, and soluble proline were higher in plants under salt stress condition. Salinity stress induced higher production in hydrogen peroxide (H2O2) and malondialdehyde (MDA) and also higher activity of catalase (CAT) and ascorbic peroxidase (APX) as antioxidant enzymes, but lower activity of peroxidase (POD). Genotypes 4s, Arg, and 386dh had generally higher enzymatic activity and other tolerant indices, and hence they can be introduced as tolerant genotypes for more study by the plant breeders. On the other hand, genotype 278s was most susceptible based on the most results. [ABSTRACT FROM AUTHOR]

The texture of boiled potato tubers is one of the most important quality traits. The variation of tuber texture is usually examined in relationship with dry matter or starch content. The objective of the work was to examine variation and stability of texture and starch content in tubers grown in various environments. Both traits were evaluated for the set of potato breeding lines and 10 table potato cultivars. The lines were developed in the program of parental lines carried out in Młochów Research Center, Poland. The environments were represented by three locations, which differed in cultivation system as well as climatic and soil conditions. The traits were influenced by the effects of genotype, location and their interactions. The effect of location on texture was not explained by the changes in starch content. The calculated stability parameters indicated that unstable expression of both traits was more pronounced and more frequent in breeding lines than in the cultivars. The short period of selection used in the development of the parental lines is not conducive to select potato genotypes with stable expression of quality traits. The starch content was at most moderately related with various characteristics of tuber texture. [ABSTRACT FROM AUTHOR]

In maize plant breeding aimed at producing a hybrid, it is necessary to characterize the parents and hybrids by their agronomic aspects and grain quality so that the processing industry may offer consumers a quality product and also improve its efficiency. This study evaluated the viscoelastic parameters of masa and the chemical and texture properties of tortillas obtained from parent lines (M-54, M55, and CML-242), two single crosses (M54xM55 and M55xM54), and one hybrid (H-70). The morphology of the maize grains and tortillas was analyzed using scanning electron microscopy. The firmness of masa obtained from CML-242 and H-70 maize was higher than that from the other maize genotypes. M-54 tortillas showed the lowest crude fiber content. Otherwise, tortillas obtained from the M55xM54 hard grain had the lowest fat content and extensibility, while H-70 tortillas showed an intermediate breaking point and extensibility. M-54 and M54xM55 tortillas were softer due to their more swollen starch granules. In contrast, rigid tortillas were obtained from CML-242 and H-70. Grain hardness causes different morphology in starch and tortilla of maize genotypes. However, grain hardness did not influence the characteristics of texture in tortillas [ABSTRACT FROM AUTHOR]

For a successful seed production, it is necessary to know the size, i.e. 1000-seed weight, since it affects the sowing rate, plant density over the vegetative period as well as the seed yield per unit area. The study was conducted in field conditions, on plots where seed production of sunflower hybrids parental components was organized. Seed production was based at three different localities. Observation was conducted during the course of three years. The study was performed on 18 different genotypes. Considering the total number of the observed genotypes, 10 genotypes represented lines based on CMS, while the remaining 8 genotypes represented restorer lines. The study showed that 1000-seed weight was higher with CMS based lines than with restorer lines, which was expected considering the branching of the restorer lines. Sunflower 1000-seed weight depended on the year of observation and the observed genotype. Year had a significant effect on 1000-seed weight.

Quantitative assessment of genetic divergence in 47 pigeonpea genotypes (22 B-lines and 25 R-lines) with respect to seed yield and yield components clustered them into 10 different groups. Among the ten clusters, cluster I was the largest comprising of 35 genotypes, representing collections from Andhra Pradesh, Karnataka and Bihar, while the clusters IV, V, VI, VII, VIII and X comprised of one genotype each. The distribution pattern of genotypes into different clusters revealed no parallelism between genetic and geographic diversity. An analysis of inter-cluster D2 values revealed higher divergence between cluster VIII and cluster IX, followed by cluster IX and X indicated that hybridization between parents selected from these clusters may result in maximum heterosis. Further, the results on cluster means revealed that there was no cluster with at least one genotype with all the desirable traits, indicating the need for judicious combination of all the targeted traits required hybridization between the selected genotypes from divergent clusters. In addition, number of seeds per pod, 100 seed weight, plant height, days to maturity and seed yield per plant together contributed for about 81.31 per cent of the total divergence and hence these traits to be emphasized during selection. [ABSTRACT FROM AUTHOR]

The study was conducted to determine the correlation and path coefficients among the yield and yield component characters in 10 parental lines and their 45 hybrids of pearl millet. Highly significant genotypic and phenotypic correlations were observed for productive tillers per plant (0.354,0.330), plant height (0.470.0.450), panicle length (0.558,0.508), panicle girth (0.377,0.343), biological yield per plant (0.598,0.471) and dry fodder yield per plant (0.490,0.425) with grain yield per plant. The path analysis indicated that dry fodder yield per plant (2.510,0.200), days to 50% flowering (1.770,0.020), harvest index (1.020,0.950), plant height (0.620,0.160) and panicle girth (0.420,0.120) had the highest direct effects on grain yield per plant at genotypic level. The dry fodder yield per plant, days to 50% flowering, harvest index, plant height and panicle girth in this study has been identified as selection criteria for obtaining good parental lines and hybrids in a pearl millet breeding program. [ABSTRACT FROM AUTHOR]

The study was conducted on the in vitro pollen germination at 26°, 28°, 32° and 35°C for 24h of male parental lines, pollen tube growth in vivo in cross pollination of female and male parental lines that make couples in four hybrids: ZP 504 su (♀ ZPPL 51 x ♂ ZPPL 67); ZP 677 (♀ ZPPL 17 x ♂ ZPPL 201); ZP 704 (♀ ZPPL 109 x ♂ ZPPL 79), ZP 611 k (♀ ZPPL 126 x ♂ ZPPL 105), and the open pollination of female parental lines of the above mentioned hybrids. Pollen germination in vitro and pollen tube growth dynamics in vivo showed different genotypic specificities with the tests applied. The obtained results were discussed in the context of reproductive biology of ZP maize lines and aimed to create the preconditions for successful management and direction of the process in practice -- seed production in certain environmental conditions. [ABSTRACT FROM AUTHOR]