Diallel Analysis of the Stay-Green Trait and Its Components in Sorghum

Oosterom, E J Van and Jayachandran, R and Bidinger, F R (1996) Diallel Analysis of the Stay-Green Trait and Its Components in Sorghum. Crop Science, 36 (3). pp. 549-555. ISSN 0011-183X

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Abstract

Stay-green in sorghum [Sorghum bicolor (L.) Moench] is an important component of post-flowering drought tolerance. This research was conducted to describe (i) stay-green as post-flowering green leaf area duration (GLAD) and its components [green leaf area (GLA) flowering, timing for onset of senescence, and senescence rate] and (ii) the expression of heterosis for stay-green in terms of heterosis for its components. The study was conducted during the 1992 to 1993 and 1993 to 1994 post-rainy season at ICRISAT headquarters near Hyderabad, India. It involved a nine-parent complete diallel, in two experiments differing in soil-water availability after flowering. Weekly estimations of % GLA were made on 36 leaves per plot. Relative (%days) and absolute (m2 days) GLAD and their components were derived from a fitted logistic function. The variances in both relative and absolute GLAD were each fully (R2 > 0.96) accounted for by their components. In spite of significant genotype × environment interactions for the component traits, the expression of heterosis for non-senescence as related to the stay-green trait was stable across experiments. The inheritance of the onset of senescence was additive, but a slow senescence rate was dominant over a fast rate. Consequently, a large relative GLAD (slow senescence) was partially dominant over a small relative GLAD. Because of the dominance of a large leaf area at flowering, the partial dominance in relative GLAD translated into overdominance for a large absolute GLAD. These results offer an opportunity for improving drought tolerance of sorghum in environments with post-flowering drought stress.

Item Type: Article
Divisions: UNSPECIFIED
CRP: UNSPECIFIED
Subjects: Mandate crops > Sorghum
Depositing User: Mr T L Gautham
Date Deposited: 18 Oct 2011 06:25
Last Modified: 18 Oct 2011 06:25
URI: http://oar.icrisat.org/id/eprint/2745
Official URL: http://dx.doi.org/10.2135/cropsci1996.0011183X0036...
Projects: UNSPECIFIED
Funders: UNSPECIFIED
Acknowledgement: UNSPECIFIED
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