Shahid Ullah Khan, Ahmad Ali, Sumbul Saeed, Yonghai Fan, Ali Shehazd, Hameed Gul, Shah Fahad, Kun Lu
Rapeseed (Brassica napus L.) is the second most widely grown premium oilseed crop globally, mainly for its vegetable oil and protein meal. One of the main goals of breeders is producing high-yield rapeseed cultivars with sustainable production to meet the requirements of the fast-growing population. Besides the pod number, seeds per silique (SS), and thousand-seed weight (TSW), the ovule number (ON) is a decisive yield determining factor of individual plants and the final seed yield. In recent years, tremendous efforts have been made to dissect the genetic and molecular basis of these complex traits, but relatively few genes or loci controlling these traits have been reported thus far. This review highlights the updated information on the hormonal and molecular basis of ON and development in model plants (Arabidopsis thaliana). It also presents what is known about the hormonal, molecular, and genetic mechanism of ovule development and number, and bridges our understanding between the model plant species (A. thaliana) and cultivated species (B. napus). This report will open new pathways for primary and applied research in plant biology and benefit rapeseed breeding programs. This synopsis will stimulate research interest to further understand ovule number determination, its role in yield improvement, and its possible utilization in breeding programs.