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A major terminal drought tolerance QTL of pearl millet is also associated with reduced salt uptake and enhanced growth under salt stress

Sharma, Parbodh C., Sehgal, Deepmala, Singh, Dhananjay, Singh, Gurbachan, Yadav, Rattan S.
Molecular breeding 2011 v.27 no.2 pp. 207-222
Pennisetum glaucum, alkali treatment, alkalinity, drought, drought tolerance, germination, hybrids, internodes, isogenic lines, leaves, potassium, quantitative trait loci, salinity, salt stress, seedling emergence, seedlings, sodium, sowing
The performance of a major quantitative trait locus (QTL) of terminal drought tolerance (DT) of pearl millet was assessed under salt stress. The test-cross hybrids of the QTL donor parent (drought tolerant, PRLT 2/89-33), QTL recipient parent (drought sensitive, H 77/833-2), and a set of six near isogenic lines introgressed with a terminal DT-QTL (QTL-NILs) were evaluated for germination and seedling emergence at 7 days after sowing (DAS) in Petri plates at four salinity levels, and at vegetative (24 DAS) and maturity stages at three salinity and alkalinity levels. Na⁺ and K⁺ accumulation, their compartmentation in different plant parts, and their effects on growth and yield parameters were evaluated. The DT-QTL donor parent and QTL-NILs accumulated less Na⁺ in shoot parts at seedling, vegetative and maturity stages, and also partitioned the accumulated Na⁺ more into nodes and internodes and less into leaves than the drought-sensitive recurrent parent. The pattern of reduced salt accumulation in the drought-tolerant parent and QTL-NILs was consistently associated with better growth and productivity in saline and alkaline treatments. It is concluded that the DT-QTL contributed by PRLT 2/89-33 exerted favourable effects on growth and productivity traits under salt stress by limiting Na⁺ accumulation in leaves.