Avinash Pandey

Evaluation of Genetic Diversity of Chilli Landraces from North Eastern India Based on Morphology, SSR Markers and the Pun1 Locus

The chilli (Capsicum sp.) germplasm found throughout North Eastern (NE) India exhibits wide variability in fruit morphology, pungency, bearing habit and crop duration. As the genetic resources of chilli landraces from this region are not well documented, it is likely that they have hitherto unknown alleles and/or genes for economically important traits. In this study, 53 chilli accessions from different areas of this NE region were evaluated for genetic diversity using various morphological characters and 50 simple sequence repeat markers. It was found that erect and campanulate fruit types are grouped in separate clusters. The number of alleles per locus ranged from 3 to 9 with an average of 5.36. The average polymorphic information content value was 0.52. Percentage variation among populations, within individuals of population and within individuals was found to be 34, 57.9 and 8.05xa0%, respectively, indicating diversity in the landraces sampled. Allele mining across acyltransferase 3 (AT3) gene in a set of landraces led to identification of new single nucleotide polymorphisms (SNPs). Sequence analysis of the 2,349xa0bp AT3 region revealed the presence of a total of 79 SNPs and 3 indels. This overview of diversity of chilli landraces from NE India paves the way for conservation and utilisation of germplasm and contributes to the development of systematic breeding strategies.

Role of informal seed system in promoting landrace diversity and their on-farm conservation: a case study of rice in Indian Himalayas

Role of informal seed system in landrace diversification, in situ conservation on-farm and sustainability in production were investigated as a case study for rice diversity in Indian Himalayas. The diachronic pattern of landrace occurrence revealed substantial increase, both in landrace number and frequency, in time. The local level seed supply in Uttarakhand Himalaya revealed that about 96% seed supply originated from informal system and a mere 4% seed supply is met from formal seed supply networks. In higher elevation ranges, beyond 1200xa0masl, largely landrace cultivation is practiced and a greater landrace diversification in traditional production was observed. Substantial variations due to environmental adaptations in niche habitats help provide important donor germplasm for crop improvement to users. Further, the population genetic structure also indicated enough diversity being maintained on-farm. Developing pathways for strengthening local level seed system for landrace diversification linked to sustainability in food production and conserving agro-biodiversity has been emphasized.

Evaluation of Genetic Diversity and Interrelationships of Agro-Morphological Characters in Soybean (Glycine max) Genotypes

Forty soybean genotypes were evaluated for agro-morphological traits and genetic parameters. Correlation and path coefficients were estimated for all these traits. Analysis of variance and mean performance for yield and its components revealed significant differences among all the genotypes for all the characters. Correlation was also found significant with yield and its component traits. A path analysis indicated that hundred seed weight had highest effect on yield. A Cluster diagram based on agro-morphological traits proposed two major clusters A and B. In the present experiment the data revealed that four principal components having greater than one eigenvalues contributed 76.2xa0% of the total variation among forty genotypes of soybean. The traits, which contributed more positively to PC1 were total pods per plant (0.430), days to maturity (0.418) and filled pod per plant (0.411). Fertility percentage (0.577), hundred seed weight (0.361) and yield per ha (0.350) contributed more positively to PC2. Number of branches per plant (0.635) and five pod length (0.644) contributed more to PC3 and PC4 respectively. MACS 1394, MAUS 612 and PS 1518 were found to be promising for mid altitudes of Meghalaya.

Assessment of genotypic variation in soybean (Glycine max)

Forty-two soybean genotypes were evaluated for their agro-morphological traits and the extent of genetic variability. Analysis of variance and mean performance for yield and its components revealed significant differences among all the genotypes for all the characters. Correlation was also found significant with yield and its component traits. The path analysis indicated that number of clusters (0.402) and number of pods (0.313) had shown highest direct effect on grain yield and thus selection based on these traits will be quite fruitful. Cluster diagram based on agro-morphological traits proposed two major clusters. The experimental data revealed that 3 principal components having greater than one eigenvalues contributed 82.66% of the total variation. Number of pods (0.508), number of clusters (0.506), number of branches (0.367), plant height (0.33) and days to flowering (0.360) were major contributors to PC1. Yield per ha (0.733) and seed weight (0.403) had contributed more positively to PC2.

Marker–trait association for low-light intensity tolerance in rice genotypes from Eastern India

Light intensity is a crucial environmental factor that affects photosynthesis and ultimately, grain yield in rice. However, no gene or marker directly associated with improved performance under low-light intensity under field conditions has been identified till date. With an aim of identifying genes and markers associated with improved performance (measured in terms of better yields) under low-light intensity, an integrated field screening, in silico and wet lab validation analysis was performed. Field-based screening of a diverse set of 110 genotypes led to the identification of two physiological and three morphological parameters critical for low-light tolerance in rice. In silico analysis using information available in public databases led to the identification of a set of 90 potential candidate genes which were narrowed to thirteen genic targets for possible marker–trait association. Marker–trait association on the panel of 48 diverse rice genotypes varying in their response to low-light intensity led to the identification of six markers [HvSSR02-44 (biological yield), HvSSR02-52 (spikelet fertility), HvSSR02-54 (grain yield), HvSSR06-56 (spikelet fertility), HvSSR06-69 (spikelet fertility; biological yield), HvSSR09-45 (spikelet fertility)] lying on chromosomes 2, 6 and 9 showing significant association (R2u2009>u20090.1) for traits like grain yield/plant, biological yield and spikelet fertility under low light. Eight rice genes [including member of BBX (B-box) family] lying within 10xa0kb distance of these identified markers already reported for their role in response to stress or change in plant architecture in rice were also identified. The eight rice genotypes, five traits, eight genes and six markers identified in the current study will help in devising strategies to increase yield under low light intensity and pave way for future application in marker-assisted breeding.

Genetic characterization of chayote [ Sechium edule (Jacq.) Swartz.] landraces of North Eastern Hills of India and conservation measure

Chayote or chow–chow is an underutilized cucurbit vegetable crop, widely cultivated by farmers in the backyards and Jhum lands for its tender leaves, fruits and tuberous root. In order to initiate crop improvement program in this crop, the present study was undertaken to assess the genetic variations in the 74 chow–chow landraces collected from the North Eastern Hill region of India. Wide variations for fruit colors, fruit length (6.5–21.5xa0cm), fruit width (4.2–10.7xa0cm), fruit weight (60–560xa0g), vitamin-C (2.6–13.8xa0mg/100xa0g), reducing sugar (0.18–2.77%), total sugar (1.09–2.94%) and phenol content (0.17–3.85xa0mg/100xa0g FW) were recorded among the landraces. All the landraces were also characterized using random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) markers. In RAPD analyses, out of 28 primers a total of 198 reproducible amplicons were formed at an average of 7.01 per primer and an overall polymorphism of 88.38%. Eight fragments were specific to landraces with light green fruits. Four fragments were observed to be specific to RCSC-22 (dark green fruits) and another four specific to a RCSC-30 (pale yellow fruits). Out of 30 ISSR, only 5 primers generated a total of 32 reproducible amplicons with an average of 6.4 per primer and overall polymorphism of 62.5%. The pair wise similarity coefficient values ranged from 0.55 to 0.96. The grouping of landraces in cluster analysis was found to be independent of their respective geographic locations. The cuttings of suckers and shoot top (2xa0months old) treated with indole-3-butyric acid (200xa0mgxa0l−1) provide an alternative for the conservation of the diverse genetic materials to the researchers.

Effect of low light intensity on key traits and genotypes of hilly rice (Oryza sativa) germplasm

Low light intensity stress is a critical abiotic stress that reduces rice yield and quality. Present study has been carried out with a set of hill rice germplasm under ambient light and low light condition. Results related to principal components analysis (PCA) revealed that grain yield, plant height and pollen viability are the most informative components accounted for 63.95 % variance among the genotypes studied under low light condition. The three main traits contributing to PCA was. IRCTN 91-84, IRCTN 91-94 and RCPL 1-9C were found to be the most tolerant genotype to low light intensity under this study. * Corresponding author KEYWORDS

Studies on Aluminium Tolerance and Morphological Traits in Rice Lines from North Eastern India

Genetic variation is prerequisite for any crop improvement program as it helps in development of superior recombinants. Forty eight genotypes were evaluated for agronomic traits, yield and characters related to Al tolerance. The components of variability revealed high magnitude and highly heritable nature of the variations. High heritability with high to moderate value of genetic advance over mean was exhibited by majority of morphological traits used in the study. Significant correlations were observed for aluminum tolerance related traits, agronomic and yield traits. Principal components analysis revealed that the first three most informative components accounted for 70xa0% of the variance. The clustering pattern as revealed by dendrogram, based on average distance, classified the accessions into five clusters. Several high performing genotypes namely, N-861, Khougjai Phou, Posimot, Aaha and Epyo were found in the study which can be used for future breeding purposes.

Evaluation of Groundnut Genotypes for Tolerance to Phosphorus Deficiency

Phosphorous (P) is one of the most deficient nutrients owing to its fixation and low mobility in acid soils. A total of 324 genotypes were screened in both P sufficient and insufficient conditions to evaluate the P uptake efficiency. Thirty-four responsive genotypes were evaluated in solution culture with two checks, ICGV 86590 and JL 24. The components of variability revealed high magnitude and highly heritable nature of the variation. Highly responsive genotypes to P insufficiency; ICG 14475, ICGV 92188, and M 68 were further tested for phosphorus uptake efficiency at 15, 30, and 45 days after sowing (DAS) along with checks in sand culture in pots. ICG 14475, ICGV 92188, and ICGV 86590 were found superior in both acquisition and utilization of phosphorus due to enhanced root production for P exploration and shoot expansion, respectively. JL 24 was poor in acquisition due to lack of response in root traits under P insufficiency.

Assessment of genetic diversity based on agro-morphological traits and genic microsatellite markers in inter-specific derivatives and cultivars of pigeonpea

In the present study, genetic diversity among 73 genotypes comprising of cultivars and stable inter-specific derivatives from pigeonpea (Cajanus cajan x C. scarabaeoides) was assessed based on thirteen agro-morphological and quality traits and 42 genic microsatellite markers. Cluster analysis based on Tochers methods of pooled fielddata of agromorphological traits from all three environment and two locations grouped pigeonpea genotypes into nine clusters. Genetic divergence was mainly contributed by days to 50% flowering (30.14%) followed by 100 seed weight (20.78%) and protein content (12.56%). The range of polymorphic information content (PIC) for microsatellites was 0.055–0.695. A total of 104 alleles were amplified with 42 SSR markers with an average of 2.48 alleles per locus. Ten alleles were unique to inter-specific derivatives. Based on Shannons information index (I), ASSR 17 was the most informative locus for all the genotypes. Two loci, ASSR114 and ASSR317 were polymorphic only among the interspecific derivatives. Cophenetic correlations were statistically significant for phenograms based on Euclidean distances and average Manhattan distance analysis. The first three principal coordinates explained 60.17% and 57.22% of the accumulated variation in case of agromorphological traits and microsatellite data respectively. The information accrued is potential for broadening the genetic base in pigeonpea.