Awn microstructural observation revealing multifunction of awn-inhibitor Gene B1 in near-isogenic lines with different awn length

Abstract

Awn is one of wheat morphological characteristics and acts as a highly effective organ for photosynthesis in wheat. Variation in awn length is controlled primarily by three major genes, most commonly the dominant awn suppressor Tipped1 (B1). So far, the function of B1 is not well understood. In this paper, we identified a pair of near-isogenic lines (NILs) containing different awn inhibition gene B1 alleles and observed microstructures and ultra-microstructure of their awns. The typical awns differences between the NILs represented by the cross-sectional area and chloroplasts number. Long awn line had a larger cross-sectional area, and more cells in various parts of tissues, especially the cells containing more and larger chloroplasts, which could attribute to a strong cytological basis for photosynthesis. The results may suggest that the gene has pleiotropic effects in the control development of awn tissue structure and grain yield.

Keywords

• Common wheat; NILs-B1; awn length; SEM; anatomy