Phenotypic and physiological aspects related to drought tolerance in sorghum

Abstract

Drought is one of the major limitations to crop productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance in sorghum. This study evaluated phenotypic characteristics and physiological parameters determine which cultivars are more drought tolerant. Signs of drought intolerance in sorghum include leaf rolling, death of lower leaves, stunted growth and low yields. Experiments were conducted using 8 and 25 sorghum accessions planted at two sites in Kenya, namely; Biotechnology Centre and Kiboko Research site, respectively, for evaluation and seeds maintenance. Based on phenotypic characteristic of the 25 cultivars evaluated, the best drought tolerant cultivars were, IS.13615, KAK1950, KBM078, E-36.1, B-35, KBM-003 and IE SV 92036. These observations were specifically deduced from their performance, root characteristics, tillering ability and leaf parameters as drought tolerance indicators. B 35 and E-36 ranked the highest relative water content in leaves, hence more drought tolerant.Key Words: Pre-anthsis, post-anthesis, Sorghum bicolor RÉSUMÉLa sécheresse est l'une des contraintes majeures à la productivité des cultures dans le monde. L'identification des outils d'étude et des caractères quantifiables pourrait faciliter le processus d'amélioration de la culture de sorgho pour la tolérance à la sécheresse. Cette étude avait pour but l'évaluation des caractéristiques phénotypiques et des paramètres physiologiques pour déterminer les cultivars les plus tolérants à la sécheresse. Les signes de l'intolérance à la sécheresse englobent l'enroulement de la feuille, la mort des feuilles les plus basses, croissance rabougrie et réduction de rendement. Les essais étaient conduits en utilisant 8 et 25 accessions de sorgho plantées dans deux sites au Kenya, à savoir le centre de Biotechnologie et le site de recherche de kiboko, respectivement, pour l'évaluation et la maintenance des semences. Basé sur les caractéristiques phénotypiques de 25 cultivars évalués, les meilleurs cultivars en terme de tolérance à la sécheresse étaient: IS.13615, KAK1950, KBM078, E-36.1, B-35, KBM-003 et IE SV 92036. Ces observations étaient spécifiquement déduites de leur performance, caractéristiques des raciness, la capacité de tallage et les paramètres des feuilles comme indicateurs de tolérance à la sécheresse. B 35 et E-36 avaient une teneur relative plus élevée en eau et par conséquent les plus tolérants à la sécheresse.

Transcriptomic Identification of Drought-Related Genes and SSR Markers in Sudan Grass Based on RNA-Seq

“…Global climate change has increased the incidence of drought worldwide across successive years (Shanker et al, 2014 ), and it has had many negative effects on plant growth such as leaf rolling, growth inhibition, and death (Mutisya et al, 2010 ), thus severely affecting agriculture. Sudan grass ( Sorghum sudanense ) is an annual warm-season gramineous forage grass (Smith et al, 1982 ; Zhan et al, 2008 ).…”

Effect of morpho-physiological traits on grain yield of sorghum grown under stress at different growth stages, and stability analysis

“…Lower stomatal conductance has been shown to result in higher TE and greater accumulation of biomass in crops (Xin et al 2009). Mutisya et al (2010) reported that high RWC was correlated to drought tolerance in sorghum. Water deficit stress that determines the grain yield is known to alter many physiological processes such as leaf temperature, stomatal conductance, transpiration, photosynthesis and respiration (Mutisya et al 2010).…”

“…Also, in the present study, grain yield was strongly correlated to number of roots/plant under stress at GS2 and control conditions. Greater numbers of roots give increased accessibility to moisture and nutrients (Patil & Biradar 2005); it has been found that drought-tolerant lines show the highest root length and weight (Mutisya et al 2010). The root traits (root length, root dry weight and root number) play important roles in overcoming moisture stress in sorghum (Maiti 1996).…”