Blend wheat AL-type hybrid and using SSRs to determine the purity of hybrid seeds

Abstract

Heterosis is a promising approach to increase wheat yield from a limited planting area. In this study, a fine quality restorer line 99AR144-1 and three stable male sterile lines, AL18A, AL36A and AL20A, were assigned as male and female, respectively. Seeds of the wheat line 99AR144-1 and three male sterile lines were mixed according to different proportions and then planted at an experimental farm at the Xinjiang Academy of Agri-Reclamation Sciences from 2013 to 2016. When the mixed sowing ratios of combinations 2 (AL36A × 99AR144-1) and 3 (AL20A × 99AR144-1) were 6 to 8%, the seed production yields were higher than the control; the yield of hybrid seed production increased by 98.8 and 19.9%, respectively. This increase was attributed to a rise in the outcrossing seed setting rate. Further, this study used the Xbarc-8 SSR (simple sequence repeat) molecular marker to identify the purity of blend hybrid seeds and establish a regression equation for hybrid seed purity testing. The coefficient of the regression equation were 0.9878 and 0.9689 respectively, which shows that the purity of hybrids can be accurately predicted by using this equation. This method can quickly and accurately identify the seed purity in mixed seed production.

Emerging Trends and Promising Technologies

“…New strategies for cost-effective hybrid seed production, e.g. blending (Nie et al 2021), apomixis (Lawit 2012), or doubled haploidy (Pazuki et al 2018), are being explored for a long time, but have not reached the stage of commercial exploitation for hybrid seed production in many species. Recently, Nie et al (2021) reported that blends of restorer and male sterile lines (AL-type cytoplasmic male sterile lines), mixed in different proportions, can result in a significant increase in hybrid seed production in wheat, though maintaining the desired genetic purity of the hybrid seed remains an issue to be resolved.…”

Hybrid Seed Production Technology

“…In order to make hybrid wheat seed production easy and cost-effective, the blend hybrid seed production method has been proposed which maximizes hybrid seed production with cost reduction. A recent study has reported that a blending of 6 to 8% restorer line seeds with the seed parent seed increased the yield of mixed hybrid seed production with higher purity (Nie et al 2021).…”