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

Abstract

Sharma, P. C., Sehgal, D., Singh, D., Singh, G., Yadav, R. S. (2011). A major terminal drought tolerance QTL of pearl millet is also associated with reduced salt uptake and enhanced growth under salt stress. Molecular Breeding, 27, 207-222. IMPF: 02.85 RONO: BB06756 Sponsorship: BBSRC RONO: BB/F004133/1The 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.Peer reviewe

Further evidence that a terminal drought tolerance QTL of pearl millet is associated with reduced salt uptake

“…It is in marked contrast to our previous results, where main stems accumulated 24% higher Na + concentrations than roots on a mean basis (Sharma et al, 2011). In the present study of short-term salinity stress applied during late flowering and post-flowering growth stages, the drought-sensitive parent H 77/833-2 accumulated 9% higher Na + concentration in its roots than the drought-tolerant parent PRLT 2/89-33, whereas in the previous study involving long-term salinity application throughout the plant growth cycle, this trend was exactly reversed.…”

Genetic Linkage Map Construction and QTL Mapping of Salt Tolerance Traits in Zoysiagrass (Zoysia japonica)

“…QTLs associated with salt tolerance have been studied widely in many species [61]-[66], but not in zoysiagrass. In this study, crossing a salt-tolerant parent with a salt-sensitive parent produced the segregating population for salt tolerance in zoysiagrass.…”

The extent of variation in salinity tolerance of the minicore collection of finger millet (Eleusine coracana L. Gaertn.) germplasm

“…Three major differences were seen in the anatomy of roots of finger millet compared with pearl millet; a crop species also known to be tolerant to salinity and drought [36]. Extensive increase in the root porosity with the presence of large aerenchymatous cells in the hypodermal cortex is an indication of requirements for greater levels of aerobic respiration.…”