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.
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.