Shrawan Singh

Genetic Diversity and Population Structure in Aromatic and Quality Rice (Oryza sativa L.) Landraces from North-Eastern India.

The North-eastern (NE) India, comprising of Arunachal Pradesh, Assam, Manipur, Meghalaya, Mizoram, Nagaland, Sikkim and Tripura, possess diverse array of locally adapted non-Basmati aromatic germplasm. The germplasm collections from this region could serve as valuable resources in breeding for abiotic stress tolerance, grain yield and cooking/eating quality. To utilize such collections, however, breeders need information about the extent and distribution of genetic diversity present within collections. In this study, we report the result of population genetic analysis of 107 aromatic and quality rice accessions collected from different parts of NE India, as well as classified these accessions in the context of a set of structured global rice cultivars. A total of 322 alleles were amplified by 40 simple sequence repeat (SSR) markers with an average of 8.03 alleles per locus. Average gene diversity was 0.67. Population structure analysis revealed that NE Indian aromatic rice can be subdivided into three genetically distinct population clusters: P1, joha rice accessions from Assam, tai rices from Mizoram and those from Sikkim; P2, chakhao rice germplasm from Manipur; and P3, aromatic rice accessions from Nagaland. Pair-wise FST between three groups varied from 0.223 (P1 vs P2) to 0.453 (P2 vs P3). With reference to the global classification of rice cultivars, two major groups (Indica and Japonica) were identified in NE Indian germplasm. The aromatic accessions from Assam, Manipur and Sikkim were assigned to the Indica group, while the accessions from Nagaland exhibited close association with Japonica. The tai accessions of Mizoram along with few chakhao accessions collected from the hill districts of Manipur were identified as admixed. The results highlight the importance of regional genetic studies for understanding diversification of aromatic rice in India. The data also suggest that there is scope for exploiting the genetic diversity of aromatic and quality rice germplasm of NE India for rice improvement.

Changes in phytochemicals, anti-nutrients and antioxidant activity in leafy vegetables by microwave boiling with normal and 5% NaCl solution

The present study investigated the changes in phytochemicals and antioxidant activities in 25 leafy vegetables with two common boiling practices viz., with 5% NaCl solution (BSW) and normal water (BNW) in a domestic microwave oven. Fresh samples (100g) were rich in polyphenols (58.8-296.9mg), tannin (402.0-519.4mg), flavonoids (148.9-614.4mg), carotenoids (69.0-786.3mg), anthocyanin (11.7-493.7mg) and ascorbic acid (245.0-314.2mg). Microwave boiling significantly (p<0.05) decreased/increased phytochemicals but none of the compounds followed same trend in all vegetables. Boiling process reduced anti-nutrients from fresh samples (FS) as observed for nitrate (4.5-73.6% by BSW and 22.5-98.8% by BNW); phytate (6.2-69.7% by BSW and 10.6-57.3% by BNW) and oxalate (14.7-88.9% by BSW and 14.5-87.3% by BNW) but saponin increased in 18 vegetables by BNW while 8 vegetables by BSW. The study revealed differential pattern of change in phytochemical matrix and anti-nutrients in vegetables by microwave boiling which will help in devising efficient cooking practices and contribute in health and nutritional security.

Analysis of Perspectives of Self-sufficiency in Vegetable Production Under Tropical Conditions

The government of India is promoting local vegetable production in Andaman and Nicobar Islands in a policy of sustainable development on tropical bay islands. There has been an increase in area and productivity of vegetables and reduced import of vegetables from the mainland. Improved technologies have been transferred to vegetable farms. However, the majority of farmers rely on private agencies for inputs and marketing activities that limit profits. Lack of cold transport, storage facilities, modern collection centers, and processing industry are still challenges to vegetable growers on islands. Use of good agricultural practices for vegetables includes limited use of synthetic chemicals in the island ecosystem. The pace of adoption of improved practices in vegetables needs to be enhanced to ensure off-season availability. Many island cultures employ organic methods by default and a small amount of effort can establish them as organic hubs for vegetable production. Rising tourism and increasing import cost of vegetables increased the necessity of structural changes in production to make islands self-sufficient in vegetable production.

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

The genetic diversity of taro (Colocasiaesculenta (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.

Random amplified polymorphic DNA (RAPD) markers reveal genetic diversity in bael ( Aegle marmelos Correa) genotypes of Andaman Islands, India

The present study evaluated genetic variability of superior bael genotypes collected from different parts of Andaman Islands, India using fruit characters and random amplified polymorphic DNA (RAPD) markers. Genomic DNA extracted from leaf material using cetyl trimethyl ammonium bromide (CTAB) method was subjected to polymerase chain reaction (PCR) with 12 polymorphic primers. A total of 476 polymorphic loci were identified with mean value of 39.66 bands per primer and 63.99% polymorphism. Application of unweighted pair group method using arithmetic average cluster analysis generated three genotypic groups. ‘Bael-5’ and ‘Bael-8’ were most similar genotypes whereas ‘Bael-7’ and ‘Bael-1’ were extreme divergent. The clusters based on molecular data were not in agreement with the morphological traits in most of the cases as low level of correlation was observed between the classification methods based on fruit characteristics and RAPD markers. The bael genotypes were found to have considerable genetic variability, demonstrating the importance of RAPD markers to analyse each genotype in a collection in order to efficiently maintain the germplasm collection for genetic improvement of bael. Keywords: Aegle, Bael, random amplified polymorphic DNA (RAPD) and genetic diversity. African Journal of Biotechnology Vol. 12(42), pp. 6055-6060

Indigenous underutilized vegetables for food and nutritional security in an island ecosystem

Indigenous plants are an important component of the traditional food and health systems of rural and tribal communities in tropical regions. However, they do not attract much attention from researchers or in commercial markets. The present study investigated 42 indigenous, under-utilized vegetable plants from the Andaman and Nicobar Islands of India for their food and ecological values. Predominantly, the plants belonged in the Cucurbitaceae, Amaranthaceae, Moraceae and Plantaginaceae families. Fifty seven percent of the vegetables were observed in home gardens and 21.4% were collected from wild habitats. Most of the indigenous vegetables were perennials (71.4%), and included trees, vines and shrubs. Commercial farmers grew mostly exotic vegetables, while many indigenous and under-utilized vegetables were preferred by tribal and local communities. Herbs with good flavour, taste and crispness were preferred in culinary preparations; vegetables with a bitter taste and unique flavour were considered best for health purposes. The indigenous and under-utilized vegetables contained a wide range of nutrients, including Ca, Fe, polyphenols, carotenoids, ascorbic acid and chlorophyll, although they also often contained anti-nutrients including nitrate, phytate, oxalate and saponins. Our findings support the greater use of indigenous underutilized vegetables as promising and locally accepted options to address micronutrient deficiencies among households in geographically challenged regions such as the Andaman and Nicobar Islands. The study also underlined the need to devise strategies for the promotion of these nutrient-rich indigenous foods to improve the nutrition and livelihoods of vulnerable communities.

Genetic Diversity in Drumstick of Andaman Islands and Their Relatedness with Probable Introduction Sites from Mainland India

Abstract The study investigated genetic diversity in Moringa oleifera Lam. samples (63) from nine islands in Andaman and Nicobar Islands (India) and their relatedness with samples (5) from their probable source regions in mainland India. The polymerase chain reaction analysis with polymorphic random fragment polymorphic DNA (RAPD) (5) and inter simple sequence repeat (ISSR) (20) markers generated 987 and 4190 amplicons, respectively. The RAPD analysis resulted into two main and eight sub-clusters and ISSR markers generated two main and five sub-clusters. Extent of similarity in 68 samples was revealed to be 49% by RAPDs to 53% by ISSR markers. Average polymorphism information content (PIC) value ranged from 0.47 to 0.50 for the studied markers. Maximum collections from the islands were grouped along with samples from Tamil Nadu, Andhra Pradesh and Kerala which suggest high level of genetic relatedness. The information on influence of ‘isle factor’ in genetic divergence of introduced drumsticks is useful for continuance of studies on genetic changes for adaptation.