Chinese adzuki bean germplasm: 1. Evaluation of agronomic traits

Abstract

A core collection of adzuki beans, representing the germplasm of Chinese land races, was screened at Warwick Australia in a replicated yield trial sown mid-summer. Grain yield, yield components, phenologic traits, vegetative characteristics, and morphologic descriptors were recorded for all accessions plus Japanese-derived check varieties. Accessions from southern China were later flowering, had smaller seed, and grew taller than those from central China. Grain yield was greatest for accessions from central China, whereas both north Chinese and Japanese check accessions were generally low yielding. The evaluation of diversity displayed trends associated with latitude of germplasm origin, which were positive or negative according to the trait. Similarly, the germplasm diversity in duration of crop growth phases and in rate of yield expression was also associated with latitude of landrace origin. Localised variations from these trends were found for seed size and for number of pods per plant. Various trends with latitude of origin were found for natural incidence of powdery mildew, for growth habit, plant height, vining and leaf colour. However, traits not associated with latitude of germplasm origin included primary and secondary seed colour, mature pod colour, and degree of branching. The evaluation suggests that selections from this greater range of genetic diversity may allow higher yielding varieties than the current Japanese-derived standards to be developed for Australia.