Rice Genotypes with SUB1 QTL Differ in Submergence Tolerance, Elongation Ability during Submergence and Re-generation Growth at Re-emergence

Abstract

Submergence tolerance is an important trait where short term flash flooding damages rice. Tolerant landraces that withstand submergence for 1–2 weeks were identified. Due to the heterogeneity in flood-prone ecosystem many different types of traditional rice cultivars are being grown by the farmers. The local landraces adapted to extremes in water availability could be the sources of genetic variation are to be used to improve the adaptability of rice to excess water stress. Greater genotypic variability was observed for plant height, elongation and survival %, absolute growth rate, non-structural carbohydrate retention capacity, chlorophyll content, different chlorophyll fluorescence parameters (FPs) characteristics, and re-generation growth at re-emergence. Twenty days submergence caused greater damage even in Submergence 1 (SUB1) introgressed cultivars compared to the 14 days of submergence. The FPs, carbohydrate content and dry weight at the end of submergence showed positive and highly significant association with re-generation growth. The presence of SUB1 associated primers, either SC3 or ART5, was noticed even in greater elongating types of rice genotypes. These genotypes possess one or more of the adaptive traits required for the flood-prone ecosystem, which range from temporary submergence of 1–2 weeks to long period of stagnant water tolerance.Electronic supplementary materialThe online version of this article (doi:10.1007/s12284-011-9065-z) contains supplementary material, which is available to authorized users.

Field level damage of deepwater rice by the 2011 Southeast Asian Flood in a flood plain of Tonle Sap Lake, Northwest Cambodia

“…The stagnant sub-1 rice may be valuable from the middle zone to the flood limit field, in years when maximum water depth was shallower but flash flood occurs. Cultivars would be needed which possess SUB1 and at the same time show some degrees of elongation due to flooding in order better to cope with the various deep water environments, and such types of germplasms lines were reported (Sarkar and Bhattacharjee 2011). Appropriate crop management was also important to cope with the dry-spell and assist plant elongation during flooding from September, as discussed by others (Bouman et al 2007;Puckridge et al 1989).…”

Characterization of Leaf Gas Exchange and Anti-oxidant Defense of Rice (Oryza sativa L.) Cultivars Differing in Submergence Tolerance Owing to Complete Submergence and Consequent Re-aeration

“…Analysis of flooding pattern in rainfed lowland of Southeast Asia reveals that about 20 million ha comes under medium-deep to deep and very deep ecology based on water stagnation. Here, the ideal response to flooding is submergence tolerance (survival under water) together with some elongating ability [4,30,32]. Is the extent of injury caused by complete submergence is alike both in tolerant and elongating type rice cultivars?…”

Variation in Expression of <i>Sub</i>1 Gene and Association with Submergence Stress Related Traits in Advance Rice (<i>Oryza sativa</i> L.) Genotypes as a Tool of Climate Change Adaptation

“…Results of PCR revealed that ART5 which is a closely linked marker in the promoter region of SUB1C a transcription-factor gene [3] showed bands in some of the genotypes while the presence of this marker was nullified in all the rest of the genotypes used in this study. …”

“…In Pakistan, approximately 70% rice farms are prone to seasonal flooding. Rice crop may be the only crop which can effectively be grown in flood prone ecosystems [3]. These floods are sometimes so damaging that rice farmers in some parts of the country lose their entire rice crop.…”

“…The experts say that the situation may is a variable polygenic locus that encodes two to three ethylene responsive factors (ERF) DNA binding proteins [11]. However, the response of this SUB1 QTL differs with the genotypes and other environmental factors [3]. In order to study these responses, an experiment was organized to screen that included 115 rice genotypes with SUB1 QTL from International Rice Research Institute (IRRI),…”