INDIAN JOURNAL OF GENETICS AND PLANT BREEDING

Marker-assisted characterization and evaluation of improved Basmati rice (Oryza sativa L.) parental lines for multiple disease resistance

Krishnan P. Abhijith — 2025-03-30

The development of improved parental lines with inbuilt resistance to major biotic stresses is a crucial step in developing promising rice hybrids since the yield advantage from the hybrids can be negated by a disease outbreak. The present study was carried out to investigate resistance to Bacterial Blight (BB), blast and sheath blight in a set of improved Basmati Putative parental lines (PPL) consisting of 59 putative maintainers and 107 restorers which were derived from multi-parent crosses involving diverse maintainers and restorer founder parents. Among the PPLs, 71 entries displayed resistance to BB, including 32 restorers and three maintainers carrying both Xa21 and xa13 resistant alleles. Moreover, 85 genotypes exhibited resistance to blast disease, with 35 of them possessing both Pi2 and Pi54 alleles for disease resistance. Overall, 108 PPLs harboured resistant alleles for BB and blast while 60 entries were found to possess the resistant allele of one or more genes governing resistance to both blast and BB diseases and notably, 20 restorers featured all four genes (xa13, Xa21, Pi2, and Pi54). As many as 22 genotypes including nine restorers and 13 maintainers were identified as resistant to sheath blight disease. However, none of them possessed the resistant allele of the QTL, qSBR11-1. Analysis of allelic frequencies revealed an upward shift of resistant alleles in this improved Basmati rice genotype panel compared to founder parents. The amalgamation of multiple genes conferring disease resistance against diverse diseases in these parental lines can bolster hybrid breeding by developing superior hybrids with inherent resistance to these major diseases.

Identification of low-light-tolerant rice (Oryza sativa L.) genotypes based on agro-morphological traits, combined stress tolerance and stability index

Swagatika Das — 2025-03-30

Low light is a major abiotic stress during the wet season, leading to an approximate 35% reduction in rice yield compared to the dry season. Developing rice varieties with improved yields and tolerance to low light conditions is therefore critical. This study aimed to identify low-light-tolerant rice genotypes using a Combined Stress Tolerance and Stability Index (CSTSI). A panel of 192 genotypes was evaluated for 12 agro-morphological traits during the Kharif (wet) seasons of 2021 and 2022. Results showed that low light significantly reduced key traits such as tiller number, grain number, spikelet number, spikelet fertility, panicle number, grain weight, biomass, and grain yield. Two-way ANOVA indicated significant genotypic variation under low light stress, with grain yield and biomass reductions of 41.96 and 28.49%, respectively. Yield Stability Index (YSI) and Relative Yield (RY) were calculated to assess genotype performance. The CSTSI was developed to evaluate overall stress tolerance among the 192 genotypes. Regression analysis revealed strong correlations of CSTSI with RY (0.897) and YSI (0.791), confirming its effectiveness in identifying low-light-tolerant genotypes. Based on the CSTSI, nine genotypes were identified as highly tolerant, outperforming the tolerant check variety, Swarnaprabha. Cluster analysis grouped the 192 genotypes into five clusters. Clusters IV and V included tolerant genotypes such as Purnandu, Ambika, Laxmichura, Chamarmani, Bhasamanik, TRB-468, VL Dhan209, Swarnaprabha, and TRB-451, which exhibited superior performance in YSI, RY, and CSTSI. In contrast, cluster I contained low-performing genotypes like Kunti, Sanwal Basumati, IR8, IR64, Pusa-834, Srabani, Sahabhagi Dhan and Khandagiri. Identifying low-light-tolerant genotypes provides valuable insights for identifying QTLs, genes, and superior haplotypes associated with low-light tolerance. These findings are critical for molecular breeding programs aiming to develop resilient rice varieties for low-light environments. Additionally, the study establishes CSTSI as a reliable parameter for screening genotypes for low-light tolerance.

QTL discovery for grain iron and zinc content in wheat: Pathway to biofortification

Raju Ratan Yadav — 2025-03-30

A deficiency of micronutrients causes hidden hunger, ultimately leading to malnutrition. Biofortification through marker-assisted breeding can be the most effective way to overcome this problem. Therefore, the identification of genomic regions (QTLs) for grain micronutrients like Fe and Zn can articulate the researchers for quicker and more accurate development of micronutrient-rich wheat varieties through marker-assisted breeding. In this study, QTLs were identified for grain Fe and Zn concentration of 214 mapping lines in F2:3 population derived from a biofortified variety, HD 3298 and M-160, a mutant line deficient for Fe and Zn developed from DPW 62150. Person correlation coefficient analysis between GFeC and GZnC content revealed that there is a significant positive correlation between the micronutrients (r = 0.95). Again, 700 SSR markers were used for genotyping of which 547 were monomorphic, while 153 were polymorphic in both the parents with a polymorphic rate of 21.11%. Linkage map construction discovered that a total of 17 QTLs were dispersed on nine chromosomes out of which five QTLs correspond to GFeC with an average LOD value of 14.73% which mapped on chromosomes, 1A and 7A. Similarly, 12 QTLs correspond to the trait GZnC with an average LOD of 14.03% and are mapped on chromosomes, 2A, 4A, 5B, 5D, 6A, 7B and 7D. The mean GFeC content of mapping lines was 34.46 mg/kg and for GZnC was 22.59 mg/kg with SE of 0.65 and 0.40, respectively. These identified QTLs can be triggered as valuable tools for advanced molecular breeding practices.

Rapid generation advancement protocol of wheat under natural day-length conditions during summer seasons in sub-tropical conditions

Naman Raj — 2025-03-30

Developing improved crop cultivars is essential for confronting adverse environmental conditions. Rapid cultivar development requires reducing crop duration through rapid generation advancement (RGA) strategies. Extreme conditions that allow five to six crops annually may not provide plant breeders the opportunity for selection based on phenological traits and also necessitate a well-equipped growth chamber. The present study aimed to develop an RGA protocol under natural daylight during the summer season in sub-tropical conditions, incorporating irrigation, and plant density modulation alongside the chilling treatment of harvested seed. Wheat cultivars HD2932 and HD3086 were grown in 4-inch plastic pots with either one or four seeds per pot. The plants grown at higher density flowered 3 to 4 days earlier than their low-density counterparts. Irrigation was stopped either at 15 or 25 days after anthesis for forced maturity in different sets of plants, and the matured seeds were harvested after 20 days of the last irrigation. Consequently, the seed-to-seed cycle was shortened to 90 to 95 days compared to the regular cropping season (140–150 days). The seeds were subjected to chilling treatment at 4°C prior to sowing, and it was observed that chilling treatment for up to 72 hours can increase germination percentage beyond 90%. The protocol standardized in the current study can help to get two wheat crops with only temperature-controlled chambers in sub-tropical conditions during the summer season. The method can be used intermittently by growing two summer crops and a rabi crop, permitting selection under intermittent moderate RGA and natural growing conditions.

Assessment of Gpc-B1/Yr36 introgressions in a popular Indian wheat (Triticum aestivum L.) cultivar PBW550 for grain yield and quality traits

Ahadu Menzir Anley — 2025-03-30

The impact of the GpcB1/Yr36 gene on agronomic attributes, grain quality parameters, and stripe rust resistance was studied in the background of the popular Indian wheat cultivar PBW550. Introgression lines SABW159 showed 21.01% enhancement in protein with no yield penalty and stripe rust-resistant reaction (10s). Similarly, SABW141 registered a 14.19% increase in protein content along with a 6.17 % yield advantage over PBW550 and the terminal disease reaction of 10S. The corresponding disease score for PBW550 was 80S. Similar trends for improvement across all three traits, viz. grain yield, GPC, and stripe rust resistance, were observed for several introgression lines, and no single yield component showed a reduction on account of enhanced protein.

Pathological and multi locus sequence analysis in Bipolaris sorokiniana inciting spot blotch of wheat reveals the predominant virulent haplotypes in India

Natasha Kashyap — 2025-03-30

Globally, a significant portion of wheat yield is impacted by Bipolaris sorokiniana, incitant of spot blotch disease. The current study aimed to unravel the diversity and virulence of B. sorokiniana in climate change scenarios. In total, 40 B. sorokiniana isolates were established based on the molecular and morphological traits which revealed BS-21 (Pusa, Bihar), BS-27, BS-33 (Sultanpur, UP), and BS-34 (Varanasi, UP) exhibited the highest mycelial growth (90 mm) at 15 DAI. The pathogen population is distributed in two major types, white/greenish black colonies (45%) and brown/dull black suppressed growth (10%). The maximum sporulation was in Pusa, Bihar isolates and the minimum sporulation was in Vidisha, MP isolates (BS-8 and BS-1). BS-21 exhibited the highest ADI (87.97%) while BS-10 showed the lowest ADI (6.86%). Upon phylogenetic analysis, the BS isolates were grouped into six clades using the multigene analysis using TEF1α, GAPDH, RPB2, BT, and ITS. The BS isolates from Ujjain, Kanpur and Panipat showed nucleotide variations in SCD1 gene, correlating with a significant reduction in pathogenicity. BRN1 gene was highly conserved among all the BS isolates. Among BS isolates, Pusa, and Bihar BS isolates were highly pathogenic. The virulence analysis for the SCD1 gene was correlated with pathogenicity. The highly virulent isolates were linked to the two most predominant haplotypes viz., Hap_2 and Hap_4 was identified from the virulence loci analysis. The present study will enhance our comprehension of B. sorokiniana’s pathogenesis and offer valuable perspectives for managing wheat spot blotch.

Marker-assisted elimination of necrosis gene (Ne1) present in wheat varieties HD2967 and HD2733

S.V. Baby — 2025-03-30

Hybrid necrosis in wheat occurs because of two dominant complementary genes, Ne1 and Ne2, located on chromosomes 5BL and 2BS,
respectively. While transferring rust resistance genes in some Indian wheat varieties, hybrid necrosis was observed with HD2967 and
HD2733, while no necrosis was observed with HD2932 and HD3059. A marker-assisted backcrossing program was initiated to eliminate
the necrosis gene present in HD2967 and HD2733. Markers linked to Ne1 (Xbarc74) and Ne2 (Leq54_LrLC10 and Leq22_LrLC10) genes were
used in marker validation using a set of genotypes. The linked markers showed the presence of the Ne1 gene in wheat varieties HD2967,
HD2733 and positive check of Ne1, C306 and Ne2 gene in Parula as that of positive check Sonalika. The wheat varieties HD2932 and
HD3059 showed the absence of Ne1 and Ne2 genes as negative checks, Agra Local and NI5439. For marker-assisted elimination of Ne1
from HD2967 and HD2733 or substitution of dominant Ne1 allele with recessive ne1 allele, HD2932 was used as a donor parent. Near
isogenic Lines (NILs) of HD2967 (RPG = 96.80%) and HD2733 (RPG = 95.55%) were identified in BC2F3 generations. Plants homozygous
for recessive allele (ne1ne1) and dominant allele (Ne1Ne1) were crossed with Ne2 carrier Sonalika (Ne2Ne2) to test the effectiveness of
marker-assisted selection. While all the F1s of Ne1Ne1 died at the seedling stage, the F1s of ne1ne1 were viable and produced normal
seeds. The present study validated the available molecular markers of Ne1 and Ne2 and used these markers to develop NILs devoid
of necrosis gene Ne1. The superior genotypes (NILs) without any necrosis gene can be used freely in developing superior male sterile
(A) lines for hybrid breeding programmes or in the transfer of genes of economic importance without fear of getting hybrid necrosis.

Assessment of durum wheat (Triticum durum Desf.) genotypes for grain yield and quality in breeding programmes under rainfed conditions

Asuman Kaplan Evlice — 2025-03-30

The primary goal of durum wheat breeding is to develop new cultivars with high grain yield to feed the growing population and with high quality to meet the requirements of durum wheat end-products. The present study evaluated 24 durum wheat genotypes including 20 advanced lines and 4 cultivars grown in four locations under rainfed conditions. Grain yield and quality traits, namely, hardness index, test weight, kernel weight and diameter, color L,a,b values, vitreousness, protein content, SDS and modified SDS sedimentations were determined. Results showed significant variations in yield and quality traits. Test weight and grain yield varied more across the environments, while color values, hardness index and both SDS sedimentations showed greater variation among genotypes. Kernel diameter, weight, vitreousness and protein content also displayed similar variation among the genotypes and across the environments. Heritability ranged from 0.24 (vitreousness) to 0.99 (color b value). Correlation and biplot analyses identified significant trait relationships. Eight advanced lines exceeded 4,000 kg/ha grain yield in at least one location. Among the tested locations, Ikizce showed the highest average yield (3,601 kg/ha) making it the most suitable for wheat production.

Wheat yield prediction through artificial bee colony-enhanced convolutional neural network

M. Lokeshwari — 2025-03-30

Crop improvement programs aim to develop high-yielding varieties, coupled with resistance to biotic and abiotic stresses with nutritional superiority. Grain yield, being a complex trait is governed by genotypes, environment, and their interaction. Growing of large number of genotypes under multiple environments and measuring grain yield and its components are tedious and resource-consuming tasks. Therefore, there is a great need for novel, cost-effective techniques to evaluate the performance of crops at the field scale through indirect selection of easily scorable traits using sound algorithms based on comprehensive data. Convolutional neural networks (CNN) are one of the most promising deep learning methods for dealing with several complex tasks including crop yield prediction, but their performance is affected by manually set hyper-parameters. To address this, we proposed the artificial bee colony optimizer to efficiently search the hyper-parameters of CNN models for predicting the wheat yield on the basis of normalized difference vegetation indices, canopy temperature and plant height. Models are developed on crop yield data using 3350 germplasm of wheat planted in two growing environments as well as two different locations during the winter season of 2020-21. When compared to other popular optimization algorithms, such as genetic algorithms and particle swarm optimizers, the proposed model is proven to be superior for predicting wheat yield in terms of root mean square error (RMSE) (66.44–80.68 g/m2) and R2 (0.88–0.91) and at the same time greatly reduced the computational time. In addition, crop yield prediction using the proposed model can support different management decisions, including timing and amount of fertilization and selective breeding.

Genetic variation for methionine, tryptophan and lysine in maize (Zea mays L.) inbred lines

Ramesh Kumar — 2025-03-30

A lack of key amino acids, including lysine, tryptophan and methionine causes nutritional imbalance in maize (Zea mays L.) grain protein. The present investigation was carried out to determine the genetic variation for kernel methionine, lysine and tryptophan content in 25 promising maize inbred lines. ANOVA revealed significant differences between the genotypes for methionine (1.56–2.96%), lysine (1.90–3.68%), and tryptophan (0.51–0.92 %) content. QIL-4-2831 (2.96%), QIL-4-2829 (2.60%), QIL-4-2830 (2.44%), QIL-4-2311 (2.42%) and QIL-4-3080 (2.39%) had the highest mean methionine content. The present findings also indicated that there was no significant correlation between methionine and lysine (r=0.14), nor between methionine and tryptophan (r = 0.09). However, lysine and tryptophan were shown to have a positive correlation (r = 0.84**). The high methionine lines can be used for developing high methionine cultivars in future crop improvement programs.

Combined analysis of fixed effect and mixed effect models aids in selection of stable and productive maize (Zea mays L.) inbreds

Himakara Datta Mandalapu — 2025-03-30

A successful commercialization of a maize hybrid does not solely depend on the heterotic vigor and yield potential but also on the seed yielding ability of the parental lines which dictates the cost of hybrid seed production. Assessing the inbreds’ stability and yield performance similarly across environments could serve as an important pre-breeding step. In this study, seventy inbred were evaluated for grain yield and other traits. Joint analysis of variance showed significant differences across environments. Genotypes contributed to the highest variation followed by genotype x environment interaction effect and environments. AMMI analysis divided the variation into two PCs, with PC₁ and PC₂ explaining 56% and 44% of the total variation respectively. AMMI, GGE biplots and BLUP based analyses were employed to study the stability of genotypes for grain yield across environments. Which-won-where biplot revealed that UMI 1260 and UMI 1266 are suitable for Coimbatore (E₁) and Bhavanisagar (E₂), while IMR 108200 and UMI 1257 are suited for Vagarai (E₃). Discriminativeness vs representativeness biplot showed that Coimbatore and Vagarai are discriminative in nature while Bhavanisagar is an ideal environment for selecting the genotypes. Multiple stability indices such as YSI, HMRPGV, WAASBY are employed to assess the stability of inbreds for grain yield. MTSI was employed to select inbreds based on multiple traits. Positive selection gains were observed for yield attributing traits, while negative gains were observed for plant height and ear height. A selection intensity of 15% is employed to select ten best inbreds though MTSI. Coincidence index at 20% selection intensity revealed high level of coincidence between WAASBY and HMRPGV, indicating the selection efficiency in using either of the indices. Genotypes UMI 1286, UMI 1276, UMI 1266 ranked consistently across all the stability indices and hence can serve well as potential parental lines for hybrid development.

Deciphering genetics and mapping of early flowering and maturity in Indian soybean [Glycine max (L.) Merr.]

Nenavath Krishna Kumar Rathod — 2025-03-30

Soybean (Glycine max L.), a major oilseed crop of India, is predominantly cultivated during the kharif season under rainfed conditions. The development of early-maturing varieties is crucial due to the short growing season and the risks posed by terminal stresses like drought and high temperatures. To determine the genetics of photoperiod sensitivity, two soybean genotypes namely, SKAF148 (photoperiod insensitive) and DS9712 (photoperiod sensitive) were crossed. The F1 hybrids of the cross SKAF148 × DS9712 indicated that early flowering is predominant under short-day conditions, while intermediate flowering occurred under long-day conditions. The F2 plants on the other hand exhibited a continuous variation in photoperiod sensitivity indicating the trait to be controlled by polygenes. For trait mapping, 519 SSR markers were used, of which 258 were polymorphic. Analysis of 250 F2 segregating population led to the identification of five QTLs for days to flowering; one QTL each on chromosome 10 (qDF10.1) and 11 (qDF11.1), and three QTLS on chromosome 19 (qDF19.1, qDF19.2, qDF19.3) explaining 44.34% of the phenotypic variance. Similarly, five QTLs were mapped for days-to-maturity; two QTLs on chromosomes 1 (qDM1.1 and qDM1.2) and one QTL each on chromosome 4 (qDM4.1), 5 (qDM5.1) and 11 (qDM11.1), accounting for 34.89% of the variance. Chromosome 19 was notably involved in flowering regulations these 3 QTLs have been validated. The proximity of some QTLs reflects their potential for yield improvement. The genetic insights and QTLs identified in the present study along with the linked SSR markers, offer valuable resources for breeding soybean varieties adapted to diverse agricultural conditions across India.

Seed-borne nature of mungbean yellow mosaic India virus in mung bean (Vigna radiata L.) occurs due to cultivar and sowing date variation

Shobharani Mruthyunjaya Swamy — 2025-03-30

Mungbean yellow mosaic India virus (MYMIV) is the major viral species responsible for yellow mosaic disease in Northern India, belonging to the genus Begomovirus, family Geminiviridae. Recently, a few of the begomovirus species were reported to be seed-transmissible which is a disputed character for begomoviruses. In the present study, the possibility of MYMIV transmission was assessed through seed collected from field-infected mungbean cultivars Pusa1371 and Pusa 9531 using serological, molecular and progeny assays for three continuous seasons with three different sowing dates. Detection of MYMIV from infected seed through direct antigen-coated enzyme-linked immunosorbent assay (DAC-ELISA) showed very low absorbance values in the range of 0.23- 0.30 at 405 nm. Polymerase chain reaction (PCR) using the total DNA from the whole seed resulted in the amplicon size of 602bp and 850bp corresponding to DNA-A and DNA-B regions, respectively. Inconsistent amplification was observed only in the whole seed and seed coat, but not in cotyledons and embryonic axes of the cultivars with the first and second sowing of kharif/ rainy season. No amplification was observed with the seed harvested from the third sowing of kharif 2021 and spring-summer of 2021 and 2022. The radicle region of the seedlings tested negative through PCR with MYMIV-specific primers. No visible symptoms were observed in 1800 raised seedlings from the MYMIV-infected seed of each cultivar. Testing of 1350 susceptible and 450 resistant cultivar seedlings through DAC-ELISA and 225 susceptible and 45 resistant cultivars through PCR showed the absence of MYMIV from the raised seedlings. Based on the results of DAC-ELISA, PCR and grow-out experiments, it was concluded that MYMIV may be seed-borne in nature but not seed-transmitted in the tested mungbean cultivars.

Elucidating combining ability and gene action for some chemo-morphological characters in grasspea (Lathyrus sativus L.)

Aditya Pratap Singh — 2025-03-30

This study aimed at the identification of good general combiners and specific crosses of grass pea (Lathyrus sativus L.) based on their combining ability and understanding of the gene action underlying the expression of various characters, including seed ODAP content. Five parents were crossed in half-diallel design and were evaluated with the resultant crosses. Most of the characters showed a broad range of genetic variability. The number of pods per plant, protein content of seed, ODAP content in seed and seed yield per plant exhibited high heritability. The expression of most characters was affected by both additive and non-additive gene action. Dominance variance without significant additive variance was observed only for the seed index. Interestingly, recessive alleles contributed more to ODAP content than dominant alleles. The parents BK-1, Mahateora, Ratan and Nirmal were good general combiners for various desirable traits and may be utilized in the further crossing program. The cross BK-1 x Ratan was the best specific combiner for days to early flowering and maturity, with higher protein content, lower ODAP content and seed yield per plant whereas the crosses BK-1 x Pratik and Mahateora x Pratik were better specific combiners for seed ODAP content and protein content. The selected crosses from this study can be used to raise segregating generations to obtain transgressive segregants for better yield and low ODAP content in seeds for future breeding programs.

Generation of biparental progenies and dissection of gene action for yield and related traits in lentil (Lens culinaris L. Medikus)

Harsh Deep — 2025-03-30

Lentil (Lens culinaris L. Medikus), commonly known as ‘masoor’, is one of the major cool-season food legumes. The present investigation
was aimed at creating new genetic variability through biparental mating-derived progenies and studying the nature and magnitude of
gene effects for yield and component traits. Biparental progenies were developed from three lentil crosses viz., PL 6 x PL 8; PL 6 x L 4147
and L 4147 x PL 7 and were evaluated alongwith F2:3 progenies in the field. The resulting progenies released useful genetic variability
including transgressive segregants. The magnitude of dominance genetic variance was higher than the additive genetic variance for
traits viz. days to 50% flowering, days to maturity, number of primary branches per plant, number of secondary branches per plant,
plant height (cm), number of pods per plant, seed diameter (mm), seed yield per plot (g), biological yield per plot (g) and harvest index.
Hybridization followed by selection at later generations is suggested for exploiting dominance gene action in these traits. Hundred
seed weight was the only parameter in which additive variance was greater than dominance variance and also showed the highest
heritability in all three crosses. Therefore, preference should be given to pure line selection, mass selection and/or progeny selection
for improvement of 100-seed weight.

Exploiting heterotic behaviour for oil yield and fatty acid content in safflower (Carthamus tinctorious L.) in India

Yengkhom Linthoingambi Devi — 2025-03-30

Safflower is considered an important oilseed crop in the world. The oil mainly contains unsaturated fatty acids like linoleic acid and oleic acid. Fatty acid profiling of F2 seeds in all the crosses was found to be good along with a good amount of oil content. The highest oil content was found for the genotype EC-755664. The highest linoleic acid was found in the cross, EC 755673 X GMU 2830 followed by GMU 6854 X GMU 1217, while crosses EC 755664 X GMU 2830 and EC 755664 X GMU 1217 had a moderate average content of both linoleic acid and oleic acid. Better content of oil and fatty acid composition was observed in the crosses as compared to their parents. The percentage of linoleic and oleic acid content in F2 seeds was good along with a high percentage of oil content. The present findings may be very useful in breeding programs on the production of hybrids with high oil and good fatty acid content and can be applied in related crop improvement work.

Comprehensive analysis of copy number variation in diverse bitter gourd (Momordica charantia L.) accessions

Parinita Das — 2025-03-30

Copy number variation (CNV), a type of large-scale structural variation, contributes substantially to genetic diversity, impacting phenotypic traits and adaptive evolution in plants. In this study, genome re-sequencing of 146 bitter gourd (Momordica charantia L.) accessions revealed over 200,000 unique CNVs, consisting of 33,8031 deletions and 200,714 duplications. A total of 5763 CNV regions (CNVRs) were identified, spanning sizes ranging from 1 to over 400 kb, with notable enrichment on chromosomes 6 and 8. Functional annotation of 992 genes overlapping with CNVRs highlighted processes related to DNA repair, pathogen defense, metabolic regulation, and bioactive compound synthesis, including terpenes and antioxidants. Gene ontology and KEGG pathway enrichment analyses indicated roles in DNA integration, stress resilience, and metabolic pathways. A significant genetic differentiation influenced by domestication and regional adaptation was observed from clustering and population structure analyses. Hierarchical and PCA clustering identified distinct groups based on geographic origin, with a marked divergence between wild and cultivated varieties, particularly among accessions from China and Africa. This comprehensive CNV analysis provides valuable insights into the genetic diversity and adaptive mechanisms of bitter gourd, supporting breeding strategies, conservation efforts, and further exploration of its genomic potential for crop improvement.

Assessment of CMS based Flue Cured Virginia tobacco (Nicoitiana tobaccum L.) hybrids for stability of marketable yield traits in light soils of Karnataka

C. Nanda — 2025-03-30

Flue-cured Virginia (FCV) tobacco (Nicoitiana tobaccum L.) cultivation in the southern transition zone of Karnataka light soils is frequently prone to drastic seasonal variations of climatic factors like rainfall, temperature and sunshine hours. Hence, it is essential to evaluate and identify the cultivars with stable and high mean performance across seasons/environments. In the present study, eight FCV tobacco CMS hybrids and three standard checks were evaluated for yield and yield-related parameters in RCBD with three replications over three crop seasons. AMMI model and GGE biplot were used to detect and characterize genotypic × environmental interaction (GEI) and to identify stable hybrids across the environments. Combined analysis of variance revealed that genotypes and environments differed significantly and GE interaction was significant for cured and bright leaf yield. AMMI II model family was adequate to explain the detected variation attributable to GEI. Two hybrids CMS 7 × A4 and CMS 10 × A4 were found to be stable with high mean performance for marketable yield traits across the seasons based on both stability parameters as well as GGE biplot analysis. Hybrid CMS 7 × A4 with YREM values near unity is likely to maintain its high leaf yield potential across environments even in the presence of cross-over GEI.

Assessment of genetic diversity and population structure in mungbean [Vigna radiata (L.) Wilczek] local collections and prominent varieties using SSR markers

Gayacharan Gayacharan — 2025-03-30

Mungbean (Vigna radiata L.) is an important legume crop in South and Southeast Asia. Assessment of genetic diversity is vital for species diversity conservation, and crop improvement programs. The present study assessed the genetic diversity of 87 germplasm collections, including 12 released varieties using SSR markers. Of the 35 markers screened, 19 were informative, generating 35 alleles with an average of 4.11 alleles per locus. PIC values ranged from 0.24 to 0.75 and expected heterozygosity averaged 0.47 for local collections and 0.41 for released varieties. Genetic variation was primarily within populations (91.3%), with low population divergence (Fst = 0.12). Local collections were more genetically diverse, offering valuable resources for future breeding programs.