Foxtail millet (Setaria italica (L.) P. Beauv.) is an ideal crop for changing climate and food habits of peoples due to its short duration, high photosynthetic efficiency, nutritional richness and fair resistance to pest and diseases. However, foxtail millet yields are low mainly due to the lack of effort for its improvement and the lack of proper utilization of existing genetic variability. To enhance the use of diverse germplasm in breeding programmes, a core collection in foxtail millet consisting of 155 accessions was established. Core collection accessions were fingerprinted using 84 markers (81 simple sequence repeats (SSRs) and three Expressed Sequence Tag (EST)-SSRs). Our results showed the presence of greater molecular diversity in the foxtail millet core collection. The 84 markers detected a total of 1356 alleles with an average of 16.14 alleles (4 -35) per locus. Of these, 368 were rare alleles, 906 common alleles and 82 the most frequent alleles. Sixty-one unique alleles that were specific to a particular accession and useful for germplasm identification were also detected. In this study, the genetic diversity of foxtail millet was fairly correlated well with racial classification, and the race Indica showed a greater genetic distance from the races Maxima and Moharia. The pairwise estimate of dissimilarity was . 0.50 except in 123 out of 11,935 pairs which indicated a greater genetic variability. Two hundred and fifty pairs of genetically most diverse accessions were identified. This large molecular variation observed in the core collection could be utilized effectively by breeders or researchers for the selection of diverse parents for breeding cultivars and the development of mapping populations.

Drought is the most predominant constraint to rainfed rice production. Identifying molecular markers associated with drought resistance traits and deploying them in marker-assisted breeding will hasten the development of drought-resilient cultivars. A total of 49 diverse rice accessions, including traditional landraces, were evaluated for plant production and root traits under natural drought stress in rainfed target populations of environment (TPE) in six successive field trials from 2010 to 2015. Significant variation for phenology, plant production and root traits under drought was noticed among the accessions. Genotyping of the rice accessions using 599 polymorphic simple sequence repeat (SSR) markers showed considerable variation among them. STRUCTURE analysis grouped the 49 accessions into three subpopulations. Similarly, three clusters were observed in Neighbor joining tree created using Nei's genetic distance. The subpopulation POP1 consisted mostly of landraces, while subpopulation POP3 consisted of advanced breeding lines and POP2 accessions from all groups. Genome-wide association mapping detected 61 markers consistently associated in two or more trials with phenology, plant production and root traits under drought in TPE. The markers PSM52 (Chr 3), RM6909 (Chr 4), RM242 (Chr9) and RM444 (Chr 9) were consistently associated with grain yield and root traits under drought. The markers PSM127 (Chr 3) and PSM133 (Chr 4) were consistently associated with yield, plant height and spikelet fertility. These markers with pleiotropic and consistent associations with yield and secondary traits under drought in TPE may be robust candidates for marker-assisted breeding for drought resistance in rice.

Drought stress is a major constraint for rice production in rainfed ecosystems. Landraces are reservoir of genes that can help in breeding drought tolerant cultivars. Utilizing the genetic potential of these locally adapted resilient germplasm using quantitative trait loci (QTL) mapping and marker-assisted breeding (MAB) will hasten development of high yielding drought resilient cultivars. A total of 60 genomic regions linked to phenology and plant production traits under drought predominant in rainfed target populations of environment (TPE) were mapped using rice lines derived from a locally adapted landrace, Nootripathu and drought susceptible elite cultivar, IR20 evaluated in three drought stress and one non-stress experiments in the field. QTLs important in rice adaptation to drought have been saturated and refined with additional markers. For example, consistent QTL, RM8085-RM3825 on chromosome 1 for grain yield under drought in TPE, with additive effect from the landrace has been narrowed down to 42.8 Kb (from 1.6 Mb) between RM11873-RM3825. Another QTL for yield under drought was also identified at RM11943 on chromosome 1 with additive effect from IR20 and is also linked to sd1 locus governing plant height. Similarly, the consistent QTL detected for days to 50% flowering (DFF), between RM314-RM6836 on chromosome 6 was also narrowed down to 279.8 Kb (from 4.9 Mb) between RM19715-RM19727. This QTL also harbours Hd1 locus regulating heading date. A QTL for yield under drought was also mapped on chromosome 6 near RM314. Both these QTLs for DFF and yield are located within the meta-QTL for yield under drought (MQTL6.1). These consistent QTLs for yield and DFF under drought in TPE with linkage or pleiotropy to sd1 and Hd1 loci mapped using rice lines derived from locally adapted landrace may be useful in MAB of rice cultivars suitable for water-limited environments.

No abstract

An Experiment was conducted at Horticultural Research Station, Udhagamandalam to trace the pattern of seed development and maturation as well as improving the germination and seedling growth of gaillardia for profuse and healthy flower production. The result revealed that seeds of gaillardia attained physiological maturity at 40 DAF (Days After Flowering) where the germination and dry weight of seedlings were at their maximum level with a moisture content of 21.4 per cent. Soaking the seeds in GA 3 @ 100 ppm for 8 hr recorded higher germination (90.0%), speed of germination (6.8), seedling length (140 cm), drymatter production (0.048 g seedling-10) and vigour index (1260) compared to other treatments. It is concluded that in order to obtain quality seeds of gaillardia, the flowers have to be harvested at 40 days after anthesis for extraction of seeds and germination of gaillardia can be improved by soaking the seed in GA 3 @ 100 ppm for 8 hr.