Abstract:

【Objective】 The main purpose of this paper was to study the performance of different types of flax germplasms at adult plant stage, explore gene resource, and give science-technology support in breeding under drought conditions. 【Method】Drought Resistance Coefficient (DC) and Subordinate Function Coefficients (SC) were used to evaluate the drought tolerance in rainfed and water irrigation treatments in Dunhuang city where the annual precipitation is less than 40 mm, and meanwhile 7 agronomic traits which are relevant to drought-resistance were studied. 【Result】 The result of study on agronomic traits indicated that drought-tolerance had different reaction degrees, that plant height and 1000-grain weight were blunt while kernel number and grain weight per spike were sensitive. According to drought-resistance value clustering analysis, flax germplasm used in this study were divided into 5 drought resistance grades, 2 belonged to grade 1, 22 belonged to grade 2, 69 belonged to grade 3, 72 belonged to grade 4, and 27 belonged to grade 5. The capacity of drought resistance of the tested cultivars was relevant to geographical origins and breeding conditions and local surrounding. 【Conclusion】 Using several agronomic traits, it is an effective way to comprehensively evaluate the drought tolerance of flax at adult plant stage by Drought Resistance Coefficient (DC) and Subordinate Function Coefficients (SC), not only the bias and the instability of single factor analysis can be avoided, but the relationship between different drought tolerance and indexes in flax can be reflected better.

Key words: flax, adult plant stage, agronomic traits, subordinate function coefficients, drought-resistance evaluation