International Journal of Agricultural Science and Research (IJASR) ISSN 2250-0057 Vol. 3, Issue 2, Jun 2013, 331-336 © TJPRC Pvt. Ltd. EFFICIENT CROSSING TECHNIQUES IN OATS (AVENA SATIVA L) A. NIRMALAKUMARI, G. THAMODARAN, R. SELLAMMAL, T. EZHILARASI & R. RAVIKESAVAN Department of Millets, Centre for Plant Breeding and Genetics, Tamil Nadu Agricultural University, Coimbatore, India ABSTRACT Efficient crossing techniques were tried to improve the seed set of several oats accessions namely UFRGS 078030-2, URS GURIA, URS TARIMBA, URS/GUAPA, URS 22, UFRGS 077026, URS-TORENA under field conditions. Crossing work was carried out for two different intervals. Seed setting percentage recorded for pollination with prior to anthesis was on an average 42 per cent. Highest seed setting was reported in GUAPA X GURIA cross combination, it was recorded 70 per cent seed setting. Lowest one was URS 22 X FAPA cross recorded only 10 per cent seed setting. Reduction in seed setting was reported in delayed pollination, it was revealed that delayed pollination considerably reduce the pollen viability and stigma receptivity. Seed setting per cent for pollination with one day after anthesis was only 18 per cent. So it was concluded that over 24 % more seed setting was achieved by following the early stage pollination. It was also reported that temperature and moisture have profound effect on seed setting, pollen viability and stigma receptivity, optimum temperature is required for anthesis and seed setting. KEYWORDS: Genotypes, Emasculation, Anthesis, Pollination, Pollen Viability and Stigma Receptivity INTRODUCTION Oats rank sixth among cereals in world production, following maize, rice, wheat, barley, sorghum and the millets. Currently, commercially available oats cultivars belong to the hexaploid species Avena sativa and Avena byzantina. Avena byzantina, also known as red oat, is close to Avena sativa L. Oats is a cereal crop and is used for human food and livestock feed worldwide (Peterson et al., 2005; Achleitner et al., 2008). As compared to the other cereal crops, oat is broadly adapted to marginal environments with low fertility soils, cool-wet and low rainfall climates (Hoffman 1995; Buerstmayr et al., 2007; Ren et al., 2007). Several investigations have observed the existence of heterosis in oats (Rothman and Bowman, 1963). Because oats are autogamous species, researchers working with this crop frequently face the problem of lack of satisfactory amounts of hybrid seeds due to the difficulty in performing crosses in standard methods (Barbosa Neto, 1985). In this study, attempt have been made to cross several oats genotypes to increase the yield of existing genotypes. Compared to other cereals, crossing in oats was tedious and found to be poor in seed set due to various factors like temperature, moisture, time of emasculation, stigma receptivity and viability of pollen. Oats is a self pollinated crop classified under chasmogamous species. Inflorescence of oats is a determinate panicle consisting of many spikelets, each of which contains two or three florets. During anthesis, the lodicules in each floret swell after water uptake and cause the lemma to diverge and establish a wide angle between it and the palea. The essential organs in the floret are exposed to the environment and subsequently the anthers dehisce releasing pollen. The pollen grains are dropped on the stigmatic branches, thus effecting self-pollination. Following pollination, the floret closes because of the collapsing of lodicules. The pollen on the stigma germinates after the floret has closed. The ambient temperature range for anthesis in the field is 25-28°C.