Abstract: The drought resistance of 41 pigeon pea (Cajanus cajan) germplasms during the germination period was examined with 10 indicators, including seed germination rate, germination index, vigor index, root surface area, and root volume. Coefficient of variation analysis, correlation analysis, principal component analysis, membership function analysis and cluster analysis were used to evaluate drought resistance. The differences of physiological responses of different drought-resistant pigeon pea materials were analyzed under drought stress. The results showed that drought resistance of the 41 pigeon pea materials was significantly different during seed germination. They could be classified into four types: highly drought resistant (1), drought resistant (10), intermediate (28), and sensitive (2). Relative vigor index, relative root-shoot ratio, relative fresh weight and relative average root diameter could be used as drought resistance evaluation indices of pigeon pea at seed germination stage. The activities of SOD, POD, and CAT in highly drought-resistant pigeon pea were higher than those of other types. Through comprehensive evaluation, 11 pigeon pea materials (D21024, D21035, D21022, D21094, D21031, D21030, D21061, D21134, D21136, D21009, and D21023) were screened out as materials with strong drought resistance, which could be widely planted in arid areas.

Key words: pigeon pea, seed germination, drought stress, physiological response.