Key construction strategies for core germplasm collection in vegetable pea ( Pisum sativum )

Core germplasm construction is one of the important means to utilize and manage plant germplasm resources. In present study, 180 germplasms of vegetable pea (Pisum sativum) were collected to study the construction strategy of core germplasm. The agronomic and yield characters were investigated, including the number of pod per plant, number of seed per pod, pod length, pod width, pod thickness, fresh mass of 100-pod, fresh mass of 100-seed, and yield. The results revealed an abundant genetic diversity in these vegetable pea germplasms. Using these data, the construction strategies of core germplasm were studied by using the minimum distance stepwise sampling (LDSS) method with four genetic distances and eight sampling ratios. Then, the construction strategies were evaluated by using the coincidence rate of range (CR) and variable rate of coefficient of variation (VR). The principal component analysis and cluster analysis were conducted to validate the representativeness of core germplasms. The results showed that Euclidean distance (ED) combining 25% sampling ratio was the best construction strategy in core germplasm construction of vegetable pea based on LDSS method. This study will lay a foundation for the core germplasm construction and efficient utilization of vegetable pea.