Raju Bheemanahalli R, Narayanaswamy Beerasandra R, Mohankumar Malagondanahalli V, Sumanth Kambalimath K, Rajanna Mavinahalli P, Mohanraju Basavaiah, Udayakumar Makarla, Sheshshayee Madavalam S
Department of Crop Physiology, University of Agricultural Sciences, GKVK, Bengaluru-560 065, India.
Zonal Agricultural Research Station, VC Farm, Mandya-571 405, India.
Funct Plant Biol. 2014 Sep;41(9):930-939. doi: 10.1071/FP13291.
Reduced spikelet fertility appears to be one of the major factors responsible for the decreased rice grain yield when cultivated under semi irrigated aerobic condition. We demonstrate that genotypes with better root systems coupled with higher cellular level tolerance (CLT) can significantly improve spikelet fertility under semi-irrigated aerobic condition in the field. A set of 20 contrasting rice accessions differing in root traits and CLT with significant molecular diversity were subjected to specific soil moisture regimes during a period between five days before and 10 days after anthesis. Lowest spikelet fertility was observed among the plants grown under water limited (WL) conditions followed by the plants grown aerobically in field conditions (AF). Deep rooted genotypes generally maintained higher spikelet fertility under both WL and AF conditions. Furthermore, genotypes that had high roots biomass as well as high CLT recorded the lowest reduction in spikelet fertility under WL and AF compared with the low root and low CLT genotype. This study emphasised the relevance of combining water acquisition and CLT for improving field level tolerance of rice to water limitation. Such genotypes recorded significantly higher grain yield under stress as well as well watered conditions. The study led to the identification of promising trait donor genotypes which can be exploited in breeding to develop superior trait pyramided cultivars suitable for semi irrigated aerobic cultivation.
在半灌溉有氧条件下种植时，小穗育性降低似乎是导致水稻产量下降的主要因素之一。我们证明，具有更好根系且细胞水平耐受性（CLT）较高的基因型能够在田间半灌溉有氧条件下显著提高小穗育性。一组20个在根系性状和CLT方面存在差异且具有显著分子多样性的水稻品种，在花期前5天至花后10天期间接受特定的土壤水分处理。在水分受限（WL）条件下生长的植株中观察到最低的小穗育性，其次是在田间有氧条件（AF）下生长的植株。深根基因型在WL和AF条件下通常保持较高的小穗育性。此外，与低根和低CLT基因型相比，具有高根系生物量和高CLT的基因型在WL和AF条件下小穗育性的降低幅度最小。本研究强调了结合水分获取和CLT以提高水稻田间水平对水分限制耐受性的相关性。这些基因型在胁迫和充分供水条件下均记录到显著更高的籽粒产量。该研究导致鉴定出有前景的性状供体基因型，可用于育种以培育适合半灌溉有氧栽培的优良性状聚合品种。
