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Characterization of flowering time response among recombinant inbred lines of WAB638-1/PRIMAVERA rice under reproductive stage drought stress
- Kehinde A. Adeboye, Olusegun A. Oduwaye, Isaac O. Daniel, Mamadou Fofana, Mande Semon
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- Journal:
- Plant Genetic Resources / Volume 19 / Issue 1 / February 2021
- Published online by Cambridge University Press:
- 17 February 2021, pp. 1-8
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- Article
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Ninety-eight high-yielding recombinant inbred lines (RILs) of WAB638-1/PRIMAVERA rice were evaluated with the parents under reproductive stage drought stress. The study aimed at characterizing flowering time response under drought stress and consequently classifying the genetic resources for efficient use in breeding programmes. Two field trials were conducted during the 2016 and 2017 dry seasons using the randomized complete block design with two replications. In 2016, 12 RILs were evaluated with the parents for the rooting attributes under drought stress and well-watered treatments. Analysis of variance revealed a significant (P < 0.05) variation among the genotypes for the traits evaluated. Drought stress reduced most of the characters in this study, including grain yield. However, the inbred lines exhibited considerable tolerance to drought stress as indicated by yield-related stress indexes, including stress susceptibility and drought tolerance indexes. Delayed flowering (FD) was recorded in 75 genotypes (including WAB638-1), while 25 genotypes (including PRIMAVERA) had no delay under drought stress compared to the control. The genotypes were grouped into flowering delay (D) genotypes (FD > 1 d) and no delay (N) genotypes (FD < 1 d), which significantly differ (P ⩽ 0.05) for numbers of days to 50% flowering. The flowering delay genotypes may be suitable for intermittent drought, while genotypes with little or no delay may be selected for terminal drought conditions. There was a significant correlation (r > 0.5) between the root length and number of days to 50% flowering. The study indicated that root parameters, such as the root length, may contribute to the drought adaptation mechanisms of the RILs.
13 - The Dynamics of Rice Domestication: A Balance between Gene Flow and Genetic Isolation
- Edited by Paul Gepts, University of California, Davis, Thomas R. Famula, University of California, Davis, Robert L. Bettinger, University of California, Davis, Stephen B. Brush, University of California, Davis, Ardeshir B. Damania, University of California, Davis, Patrick E. McGuire, University of California, Davis, Calvin O. Qualset, University of California, Davis
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- Book:
- Biodiversity in Agriculture
- Published online:
- 05 June 2012
- Print publication:
- 23 February 2012, pp 311-329
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Summary
The relationship between domesticated crop species and their wild ancestors has fascinated geneticists and evolutionists for over 150 years (Darwin 1859, 1868). Over the past century, growing awareness of the value of plant genetic diversity has led to global efforts to preserve genetic resources (Vavilov 1926, Plucknett et al. 1983, Chang 1984, Plucknett 1987, Harlan 1992). More recently, tools for investigating genetic diversity and evolution at the molecular level have provided new opportunities to investigate the process of crop domestication and to more efficiently utilize natural variation in crop improvement (Tanksley and McCouch 1997, Hoisington et al. 1999, Wing et al. 2005, Doebley et al. 2006, Dubcovsky and Dvorak 2007, Johal et al. 2008).
Domestication
Over the course of domestication, plant species undergo a series of profound phenotypic changes that result from human selection on diverse, wild populations. The genetic changes responsible for the suite of traits that differentiate domesticated plants from their wild ancestors are referred to as the “domestication syndrome” (Hammer 1984). These may include nondehiscence or nonshattering (lack of seed dispersal at maturity), more compact growth habit, reduction in seed dormancy, enhanced size and yield of edible plant parts, reduced toxicity, and changes in the reproductive system, generally toward increased rates of self-pollination or vegetative propagation (Simmonds 1979, Gepts 2004). Plants may be cultivated for hundreds or thousands of years before they are domesticated; until a plant has been modified to the extent that it can no longer survive without human intervention in its natural environment, it is not considered completely domesticated. The domestication of plants and animals had a profound impact on the structure and interactions of human societies. Most notably, humans transitioned from hunting–gathering to agriculture as the main form of food acquisition, allowing them to live sedentary lives and introducing the potential for food surpluses, population expansion, occupational specialization, and social stratification.