Agro-Morphological Evaluation of Rice (Oryza sativa L.) for Seasonal Adaptation in the Sahelian Environment

Abstract

Abstract:In the Sahel zone of West Africa that extends from Senegal to Chad, temperatures can vary from less than 15˝C to 25˝C from November to February. These low temperatures affect the growth, development and yield of rice plants, and therefore constitute a major constraint to rice production in the Sahel. In order to identify rice varieties tolerant to cold stress at different developmental stages, a diverse set of 224 rice germplasm was evaluated for yield and yield-related traits in Ndiaye, Senegal, using three different sowing dates. The first sowing date (October 2010), was chosen so as to expose the rice plants to cold stress at the reproductive stage while the rice crop planted at the second sowing date (January 2011) experienced cold stress at the vegetative stage. The third sowing date (July 2011) was the normal planting date for irrigated rice in the Sahel and it served as the control date when the crop does not experience any cold stress throughout its growth cycle. Among the data collected, significant genetic variation was detected and genotype-by-environment interaction was also significant for the traits. At the vegetative stage, cold stress reduced tillering and plant vigor and delayed flowering but increased yield, whereas at the reproductive stage, aside from delaying flowering, cold stress also inhibited panicle exsertion and reduced panicle length, spikelet fertility, grain filling and strongly reduced yields. Principal Component Analysis and correlation analysis using agro-morphological traits helped to identify genotypes that were tolerant to cold stress at either the vegetative or the reproductive stage and the traits associated with high yield under cold stress at each of these stages. Our results can be used to develop cold tolerant rice varieties adapted to double cropping in the Sahelian zone of West Africa.

Identification Of New Sources Of Rice Genotypes (Oryza Sativa L.) Tolerant To Cold Stress

“…Lower tiller number was exhibited under stressed conditions suggesting that cold stress affected tillering ability. Similar result were obtained Shimono et al (2007) and Ndour et al (2016) who reported that low temperature at seedling stage reduced tillering ability.…”

Analyses of yield related agronomic traits of Malaysian rice varieties

“…The number of days-to-flowering was found to have a moderate positive correlation to the number of tillers (r=0.372; p<0.01) and panicles per plant (r=0.345; p<0.01) since the number of tillers was positively correlated to the number of panicles (r=0.965; p<0.01). A similar trend was observed for the days-to-mature and the tiller number (r=0.470) when 224 rice accessions with different origins were evaluated at a research station of the Africa Rice Centre under the Sahelian environment (Ndour et al, 2016). In addition, a study by Seo et al (2018) on 87 rice accessions from six countries found that days-to-50% flowering and days-to-80% maturity were positively correlated with tiller number and panicle number.…”

Evaluation and Selection of Fine and Semi Fine Rice Grain (Oryza sativa L.) Genotypes for Agro-Morphological Traits under Augmented Block Design in Temperate Conditions of Kashmir Valley

“…In this study, the early maturing genotypes with high yield were IVT.1M(H)-2817, IURON-20, IURON-8, IURON-10, IRTON-23 and IRTON-25. Also (Ndour et al, 2016;Ranaweke et al, 2014) found that early maturing genotypes were more adapted to temperate climatic conditions than late late maturing ones because low temperature affects the growth, development and yield of rice plant and constitute a major constraint to rice production.…”