Male-sterile parents for breeding landrace-based topcross hybrids of pearl millet for arid conditions. I. Productivity, responsiveness and stability

Abstract

The pearl millet (Pennisetum glaucum) topcross hybrids (TCHs) based on adapted landrace pollinators have an advantage of improving yield potential while maintaining adaptation to arid conditions. We compared 39 male-sterile (A) lines of pearl millet In testcross combinations with the Early Rajasthan Populations (ERAj Pop) topcross pollinator (TCP) in 9 Rajasthan environments to assess productivity, responsiveness and stability of TCHs under arid zone environments. Thp.re was a wide ran~e in the observed mean grain yield (400-1500 kg ha-) across environments. The differences among test environments and TCHs were highly significant for biomass and grain ar\d stover yields. The major determinant of grain yield was biomass productivity. Thus for improving the grain yield in TCHs while maintaining stover yield, improvement in biomass production without necessarily altering harvest index appeared more promising, rather than improvi.1g the harvest index. There was a good choice among the tested A lines to produce grain or dual purpose hybrids and the best A lines for this purpose were 5054A, 81A, ICMA 91444, ICMA 92333 and ICMA 97333. Only a few A lines (5054A, 81A, ICMA 88006, ICMA 92333 and MAL 3A) produced TCHs which were more responsive than ERajPop to better environments in terms of both biomass and grain yield. For responsiveness of both and stover productivity, only three A lines (5054A, ICMA 88006 and ICMA 92333) produced hybrids that were equal to or better than pollinator. However, relatively large number of A lines produced TCHs with good stability for both grain and stover yields. The line ICMA 92333 proved to be the most promising to produce hybrids possessing high yielding ability and that are also responsiveness to better environments and provide stability for both grain and stover yields across a range of arid zone environments. Results indicated that considerable higher proportion of TCHs based on A lines bred In target environments rank among top for productivity than those produced on A-lines bred elsewhere which underlines the importance of selection in target environments.