Significant cell differences in pod ventral suture in shatter‐resistant and shatter‐susceptible common vetch accessions

Abstract

AbstractCommon vetch (Vicia sativa subsp. sativa L.) is a self‐pollinating annual forage legume with high nutritional value. However, pod shattering can cause severe yield loss at maturity and therefore is a significant trait for crop improvement. Our previous studies indicated that the ventral suture is critical to pod shattering in common vetch. To better understand the anatomy of the ventral suture, we evaluated eight shatter‐susceptible and 18 shatter‐resistant accessions for pod dehiscing characteristics over three consecutive years by comprehensively comparing the vascular bundle anatomical structure of the ventral suture. Four traits, specifically vascular bundle cell volume, bundle cap slope, single vascular bundle width, and external valve margin cells, were significantly different between the shatter‐susceptible and ‐resistant accessions. We found that the shatter‐resistant common vetches had a larger vascular bundle cell volume and bundle cap slope, an increased single vascular bundle width, and external valve margin cells that were significantly thicker than those of shatter‐susceptible accessions. All of the shatter‐susceptible pods had clear abscission layers. On the basis of these data, we propose a seesaw model of pod shattering in common vetch. Our morphological traits provide a novel insight into the pod shattering mechanism of common vetch, which will be valuable for breeding shatter‐resistant legumes.