Hybrid Alfalfa Seed Production Using a Female‐Sterile Pollenizer¹

Abstract

A recently discovered female‐sterile trait in alfalfa (Medicago sativa L.) was used as a male pollenizer along with three cytoplasmic male‐sterile clones to study the feasibility of mixed plantings for hybrid alfalfa seed production. Rows with mixed stands of male‐sterile (seed parent) and female‐sterile (pollenzier) clones produced significantly more seed than alternate rows of seed parent and pollenizer clones. Leafcutter bees [Megachile rotundata (Fabricius)] served as pollinators. Significant differences were noted among cytoplasmic male‐sterile clones for seed set. Their average yield was only 76% of the first‐year seed yield in an adjacent experiment. Commercial lines with the femalesterile trait and more attractive cytoplasmic male‐steriles are needed before hybrid seed yields will equal those of conventional synthetics.

Transcriptome Analysis of a Female-sterile Mutant (fsm) in Chinese Cabbage (Brassica campestris ssp. pekinensis)

“…Studies have been performed on the biological characteristics, development, genetic methods, and potential applications of female sterility (Brown and Bingham, 1984; Luo et al, 1996; Daskalov and Mihailov, 1998; Xiao et al, 1998; Zhong et al, 1998; Li and Zheng, 2002; Liu et al, 2003; Sun et al, 2009). Female-sterile mutants have been used to identify regulatory genes that influence ovule and female gametophyte development.…”

Further mapping of quantitative trait loci for female sterility in wheat (Triticum aestivumL.)

“…In capsicum and clover, female sterile lines have been used as the pollinator in hybrid seed production to shorten the parental distance and to obtain a higher seed yield (Brown & Bingham, 1984 ;Daskalov & Mihailov, 1988). In wheat, Gotzov (1979) firstly reported a female sterile material.…”

Efficient mapping of a female sterile gene in wheat (Triticum aestivumL.)

“…The MS line, generating a gynodioecy of plant species, can be used as pollen acceptor (female plant) in hybrid seed production of the selfing plants (Budar et al, 2003 ;Sodhi et al, 2006). On the other hand, the female sterile line, reflecting the evolution of a plant species from a gynodioecy to a dioecy, can be used as a pollenizer in a new hybrid seed production system in which both parents are mixedly sown to generate hybrid seeds (Brown & Bingham, 1984;Daskalov & Mikhailov, 1988;Sreiff, 1997). And this can also provide an opportunity to investigate sex phylogeny and evolution in higher plants (Maurice et al, 1994 ;Charlesworth & Wright, 2001;Delph, 2003).…”

“…Many female sterile materials have been found in various plants such as barley, rice, soybean, sugar beet, rapeseed, ramee and roselle (Jassem, 1971 ;Hanna & Powell, 1973;Ahokas, 1977;Ling et al, 1991;Vaidya, 1994). Female sterile lines in capsicum and clover have been used as pollinators in their hybrid seed production to shorten the parents' pollinating distance and to obtain higher hybrid seed yield (Brown & Bingham, 1984;Daskalov & Mikhailov, 1988). A female sterile variant in wheat was first reported in Hungary (Gotzov et al, 1979), of which the lower self-reproduction ability is a key issue that needs to be solved.…”