Path analysis of yield and mutation analysis of agronomic traits in Lolium multiflorum

Italian ryegrass (Lolium multiflorum) is an annual forage grass widely grown in southern China, and it plays an important role in modern prataculture and animal husbandry. In this study, agronomic traits of 13 Italian ryegrass materials were measured in 3 critical growth periods to identify the primary indexes of forage yield. The results showed that variations in main agronomic traits of Italian ryegrass were abundant and its coefficient of variation ranged from 4.37% to 27.91%. The fresh weight per plant had significant correlation with width of inflorescence, number of internode, number of tillers, and crown diameter; Meanwhile, the dry weight per plant had significant correlation with natural height, straighten height, length of internode, length of flag leaf, internode diameter, width of second leaf and width of flag leaf. Principal component analysis, regression analysis and path analysis showed that the key factor was plant-type factor affecting fresh weight per plant, expressed by number of tillers and crown diameter. On the other hand, leaf shape factor was key factor affecting dry weight per plant, concretely expressed as the difference of length and width of flag leaf and second leaf.