Simple sequence repeat (SSR) markers linked to drought tolerant traits in selected Sudanese rice (Oryza sativa L.) genotypes
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Date
2018
Authors
Bashier, Ahmed
Masanga, Joel
Kariuki, Wariara
Runo, Steven
Journal Title
Journal ISSN
Volume Title
Publisher
Academic Journals
Abstract
Rice growth and productivity are affected by biotic and abiotic stresses; key among them being
drought. Conventional breeding for drought tolerance is slowed down by the complex nature of
mechanisms underlying this stress although molecular markers offer a promising approach. Plant
exposure to drought stress leads to a significant effect in chlorophyll content and reduction in
photosynthesis. In this study, 23 Sudanese rice (Oryza sativa L.) genotypes under greenhouse
conditions for drought tolerance were examined. The study focus on tracking changes in chlorophyll
content under stress (by withholding water and later rewatering) and further screened them for DNA
polymorphisms using simple sequence repeat (SSR) markers. The results showed that genotypes
IR11A306, IRRI 154, NERCA 6, IR12N 240, NERICA 4, Wakra and IRRI 150 exhibited high drought
tolerance based on the assay. After dehydration, IR11A306 recorded the highest increment in total
chlorophyll while IR11A483 showed the highest reduction followed by NERICA 15, IR11 N121, IRRI 168,
NERICA 7, NERICA 1, NERICA 14 and Nipponbare. When plants were rehydrated and total chlorophyll
measured, the highest increase and best recovery were observed in IR74371-70-1-1 followed by IRRI
168, IRRI 147, Nipponbare, Kosti 2, IAC 165 and Umgar. Genotype IR11A306 showed the least reduction
in chlorophyll followed by NERICA 15, IRRI 150, IRRI 122, IR12N 240, IRRI 154, NERICA 16, NERICA 4
and Wakra. Eighteen out of the 19 primers tested showed amplification of the SSR markers generating
569 alleles that ranged between 13 and 113 alleles per marker. These alleles further produced
polymorphism information content (PIC) values of 0.51 to 0.99 per marker. The assay helped select
genotypes that showed a steady recovery of chlorophyll content following drought stress while the
markers studied could be useful for future molecular breeding for drought tolerance in rice.
Description
Research Article
Keywords
Chlorophyll, Drought tolerance, Polymorphism, Rice, Simple sequence repeats (SSR), Sudanese genotypes
Citation
African Journal of Biotechnology Vol. 17(20), pp. 649-659, 16 May, 2018 DOI: 10.5897/AJB2018.16466