Evaluation of mustard genotypes [Brassica juncea (L.) Czern and Coss] for quantitative traits and character association of seed yield and yield components at sub Himalayan region of West Bengal (India)

Brassica juncea is an important industrial and commercial oilseed crop grown primarily in India. This study aimed to assess 56 genotypes of Indian mustard to quantify genetic diversity, which aids the breeder in identifying genetically divergent parents to evaluate the proportional contributions of various components towards overall divergence. All the 56 Indian mustard genotypes were tested in RBD with three replications for 2 consecutive years i.e. 2016-17 and 2017-18 during the rabi season. Observations were recorded for 11 yield and its attributing traits. The findings revealed that height up to first branching, aphid count, penetration force and seed yield per plant had maximum PCV and GCV signifying that genetic factors have a greater impact on the inflow of these traits. Height up to first branching, secondary branches per plant, primary branches per plant, siliquae per plant, aphid count and 1000 seed weight had strong heritability combined with GA as % of mean. These indicate that the traits were controlled by additive gene action. Seed yield per plant was significantly correlated with penetration force and siliquae per plant. As a result, it's reasonable to predict that improving these traits by selection, could lead to significant yield gains. Four of the eleven PCs had eigen values greater than 1.0, accounting for 69.94% of the variance. PC I, which explained 30.31% of the overall variance. Mahalanobis D2 statistics revealed considerable genetic diversity among the genotypes. 56 genotypes were distributed into 7 clusters. This is anticipated that genotypes within a cluster are almost genetically related to one another. Cluster VII and II showed maximum inter-cluster divergence. From a breeding perspective, a divergence analysis revealed that genotypes like SKJM-05, RNWR-09-3, RW-351, B-85, DRMR-4001, RGN-386, TM52 276 and SKM-1313 can be selected as genetically divergent parents for hybridization to obtain desirable segregants

Efficiency of RAPD and SSR markers in assessing genetic diversity in summer onion (Allium cepa L.) genotypes

The genetic diversity assessment of agricultural crops is crucial for breeding programs aimed at enhancing crop yield, resistance to diseases, and adaptation to changing environmental conditions. In the present investigation, a comparative genetic relationship in sixteen onion genotypes was assessed utilizing dominant (RAPD) and co-dominant (SSR) marker systems. Ten RAPD and nine SSR markers showed genetic diversity remarkably and produced 503 and 107 amplicons respectively. Spearman rank correlation was used to compare the different efficiency parameters in two marker systems with respect to sixteen onion genotypes. The genetic relationship based on similarity matrix values between a pair of cultivars was higher for SSR markers than for the RAPD marker system. OPC-04 (RAPD primer) and ACM-004 (SSR primer) witnessed the highest poly-morphic bands along with other polymorphic markers that proved to be useful in grouping onion genotypes. Finally, dendrograms were constructed and compared following the mantel test to find out the genetic diversity among the germplasms. This study will be effective for a selection of efficient primers and suitable marker systems to distinguish the onion genotypes in the future

A comparison of efficiency parameters of SSR markers and genetic diversity analysis in Amorphophallus paeoniifolius (Dennst.) Nicolson

ABSTRACT Amorphophallus (elephant foot yam) is an herbaceous edible aroid crop which belongs to the family Araceae. The study was undertaken to identify the efficient SSR primer that could differentiate a set of 12 elephant foot yam genotypes. Various efficiency parameters, namely, Polymorphism Information Content (PIC), Marker Index (MI), Resolving Power (RP) and Diversity Index (DI) were studied for 11 primers. The relationship between the parameters was studied using Spearman rank correlation coefficient. Discrimination analysis was done to find out the most effective parameter. Finally Principal Coordinate Analysis (PCoA) and dendrogram was done to find out the genetic diversity among the germplasm. The SSR markers under this investigation will facilitate further studies in population genetics and utilization of A. paeoniifolius

Exploring the Genetic Variability for Yield Attributing Traits among the Indigenous and Exotic Collection of Wheat in Cis-Himalayan Region of West Bengal, India

A field experiment was conducted at Instructional Farm, Uttar Banga Krishi Viswavidyalaya, during the 2018-19 rabi season to study the genetic components and genetic variability based on eleven number of quantitative traits in 254 bread wheat lines, which were collected from NBPGR, New Delhi. Analysis of variance for treatment showed high significance for all the traits except grain yield polt-1. Estimated GCV and PCV were high for awn length, peduncle length, plant height and AUDPC. Plant height (97.83), awn length (95.49), peduncle length (94.88), test weight (90.98), days to 50% flowering (87.66), number of grains spike-1 (70.33) and spike length (62.3) showed high heritability along with a high degree of genetic advance. Finally, 254 wheat accessions were grouped into three clusters based on the dendrogram analysis using the ward method

Species Diversity and Community Structure of Arthropod Pests and Predators in Flax, Linum Usitatissimum L. from Darjeeling (India)

ABSTRACT The species richness and relative abundances of different aboveground plant-dwelling pest and predator species were assessed in flax (Linum usitatissimum L.) ecosystem under mid-hill conditions of eastern Himalayas. The experiment was conducted in winter seasons during 2004-2013 at the Regional Research Station (Hill Zone), Uttar Banga Krishi Viswavidyalaya, Kalimpong, West Bengal, India. Twenty five species of phytophagous arthropods under 13 families were observed belonging to 6 different orders. The gram pod borer, Helicoverpa armigera (Noctuidae: Lepidoptera), aphid, Myzus persicae (Aphididae: Hemiptera), shield bug, Plautia fimbriata (Pentatomidae: Hemiptera) and leaf webber, Nacoleia sp. (Pyralidae: Lepidoptera) were found as the most common and major insect of flax. In terms of species composition, Hemiptera and Lepidoptera occupied top position (nine species) while Coleoptera ranked second position (five species). By the size of population, aphid was found to be the most frequent species followed by shield bug and leaf webber. Although, the incidence of gram pod borer was low in the field, it was the major pest of flax in respect of bud and capsule damage. The Gini-Simpson index and Effective number of species for the pest faunal complex of flax was calculated as 0.914 and 11.628, respectively. Similarly, 16 species of predatory arthropods under nine families were observed belonging to 7 different orders. The lynx spider (17.24 %) and 7-spotted lady beetle (15.52 %) dominated the predatory community by sheer number. The Gini-Simpson index and Effective number of species for the predatory fauna was derived as 0.898 and 9.804, respectively