Genetic variation and gene flow estimation of <Emphasis Type="Italic">Nepenthes khasiana</Emphasis> Hook. F- A threatened insectivorous plant of India as revealed by RAPD markers

Random Amplified Polymorphic DNA (RAPD) markers were utilized for determination of diversity within and among the three populations of Nepenthes khasiana Hook f., a threatened insectivorous plant of Meghalaya (India). A total of 90 bands were generated from 10 random amplification polymorphic DNA (RAPD) primers of which 71 were found to be polymorphic (78.89%). Nei’s gene diversity (h) ranged between 0.124–0.201 with overall diversity of 0.228 while Shannon’s information index I) values recorded between 0.187–0.308 with an average value of 0.352. The values of gene flow (Nm = 1.284) and the diversity among populations (0.280) recorded demonstrates higher genetic variation within the population. AMOVA analysis revealed a low level of genetic variation (21.96%) among the populations. This study indicates that some variation still exists within and between the existing populations of N. khasiana, thus, these populations could provide materials for re-establishing of this important rare and threatened species.     

Diversity of 21 taro (Colocasia esculenta (L.) Schott) accessions of Andaman Islands

The genetic diversity of taro (Colocasia esculenta (L.) Schott.) accessions growing naturally in Andaman Islands was analysed using morphological and DNA markers. Twenty one representative samples of C. esculenta from different parts of Islands in addition to three commercial varieties as reference genotypes were used in study. About 63% phenotypic variation was observed in C. esculenta A total number of 491 amplified fragments were obtained of which 347 showed polymorphic banding patterns. The accessions were grouped into two major clusters with both RAPD and ISSR markers with 56 and 57% diversity, respectively. The reference genotypes were grouped into one group and island population in other cluster. Both marker systems divided population into two sub clusters and showed correlation with morphological parameters. The diversity pattern observed in present study showed rich genetic diversity of C. esculenta in Andaman Islands provided simple strategy for reducing repeatability of taro germplasm in gene banks. The study also suggested pre-evaluation of germplasm using molecular and morphological markers to enhance efficiency of exploration trips.     

New sources of downy mildew resistance in cauliflower and their prospects in resistance breeding

European Journal of Plant Pathology - 204 genotypes of cauliflower were screened against downy mildew (DM) through challenge inoculation during 2019–20 and 2020–21 and 12 genotypes were...     

Crop wild relatives in Andaman and Nicobar Islands,India

Andaman and Nicobar Islands, India is a geographically insulated biodiversity rich centre in tropical region. The islands are endowed with huge plant diversity comprising of 3219 species of 299 families and 1251 genera. The present study aimed to develop a systematic list of crop wild relatives (CWR) in the islands using information from available literature and also by ground survey. A total of 38 visits were made in all three districts of the islands and observed the crop wild relatives. In total, 153 wild species from 76 genera of 27 families were found to be related to crop plants. The list includes 34 endemic and 4 species of rare occurrence. These species are vital constituent of gene pool which can be explored for rare but novel traits of economic significance. Wild species were found to be abundant in Anacardiaceae, Musaceae, Fabaceae, Zingiberaceae, Myristicaceae, Orchidaceae and Cucurbitaceae. The listed CWRs have potential to create variability and diversify the genebanks. These CWRs grow well in tropical islands in spite of prevalent biotic and abiotic stresses. The information documented will be useful for germplasm exploration, pre-breeding and devising strategies for conservation.