Effect of cytoplasm and cytoplasm-nuclear interaction on combining ability and heterosis for agronomic traits in pearl millet {Pennisetum glaucum (L) Br. R}

Abstract

Cytoplasmic male sterility (CMS) is considered an efficient genetic tool in pearl millet hybrid breeding. Of the several CMS sources available in pearl millet, A 1 is the only CMS widely exploited to produce commercial hybrids in India. To explore the possibility of using alternate CMS sources, we studied the cytoplasmic effects of different CMS sources on agronomic characters in pearl millet. Five CMS (A) lines representing A 1 , A 2 , A 3 , A 4 and A 5 cytoplasms, their respective maintainer (B) lines and eight restorer (R) lines were used to generate 40 A · R and B · R experimental crosses. The experimental material was evaluated at two different locations in India. Analysis of combining ability and heterosis revealed that A 4 and A 5 cytoplasms had desirable effects for earliness. The A 5 CMS was found to be particularly promising, as compared to other CMS sources for improving grain yield. The study also indicated that the cytoplasmic effects on general combining ability (GCA) for various agronomic characters were largely non-significant. However, cytoplasmic effects on specific combining ability and heterosis were found to be modulated by cytoplasmicnuclear interactions and influenced by the environmental conditions. The study also demonstrated the advantage of utilizing diverse malesterile and restorer combinations in maximizing the productivity as well as for genetic and cytoplasmic diversification of hybrids in pearl millet.

Analysis of Cytoplasmic Effects and Fine-Mapping of a Genic Male Sterile Line in Rice

“…Our study showed that the cytoplasmic effects of h 2 s on yield and GCA of yield were positive and significant in both years, suggesting that h 2 s may be more useful in improving rice yield than CMS. GMS does not have male sterile cytoplasm which is responsible for negative cytoplasmic effect on agronomic traits in the CMS [1], [5], [31]. For this reason, the cytoplasmic effects are probably positive in the GMS as h 2 s .…”

“…CMS cytoplasm has been reported to have substantial genetic effects on various traits of hybrid rice [1], [2], [3]. Studies of the cytoplasmic effects of CMS show that the effects within a type of cytoplasm vary across different agronomic traits in hybrid rice and that the effects on one agronomic trait vary among different types of cytoplasm.…”

Seed parent breeding efficiency of three diverse cytoplasmic-nuclear male-sterility systems in pearl millet

“…In another study that compared isonuclear hybrids with A 1 and A 4 cytoplasm in a single environment, 8% higher yield of A 4 -hybrids was observed (Yadav 1996). On the other hand, Chandra-Shekara et al (2007) reported negative eVect of the A 4 CMS system and positive eVect of the A 5 CMS system on grain yield in pearl millet, though these diVerences were signiWcant in only one of the two environments. This study, however, was not based on isonuclear A-lines and involved a set of common pollen parents, all of which not necessarily produced fertile hybrids on the A 4 -system A-lines and none produced fertile hybrids on the A 5 -system A-lines.…”

Cytoplasmic Effects on the Agronomic and Physiological Traits of Dual‐Purpose Genic Male Sterile Substitution Lines of Rice

“…The cytoplasmic effects in crop breeding and heterosis utilization, particularly in three-line rice, have drawn substantial attention (Cailin et al, 1998;Tang, 2003;Chandra-Shekara et al, 2006;Tada, 2007;Barr and Fishman, 2010;Ngangkham et al, 2010;Cui et al, 2012;Byeonet al, 2015). Their genomes encode proteins that are not only related to the functions of these organelles but also participate in other physiological activities.…”

“…Their genomes encode proteins that are not only related to the functions of these organelles but also participate in other physiological activities. The cytoplasmic effects in crop breeding and heterosis utilization, particularly in three-line rice, have drawn substantial attention (Cailin et al, 1998;Tang, 2003;Chandra-Shekara et al, 2006;Tada, 2007;Barr and Fishman, 2010;Ngangkham et al, 2010;Cui et al, 2012;Byeonet al, 2015). The cytoplasmic sources of two-line sterile lines are freely selected, but the genetic effects of cytoplasm on the utilization of heterosis have not been thoroughly understood.…”