ANALYSIS ON FACTORS AFFECTING SEED PRODUCTION OF MALE-STERILE LINES IN ALFALFA

Morphology of the MS-4 male-sterile line of Medicago sativa L.is very similiar to that of Medicago varia Martion.CV.Caoyuan NO.1'.The two alfalfa lines are different in the size and shapes of pollen grain.Minor differences were also found in the morphology of the stigma.In Huhhot area,pollinating insects showed little preference to the flowers of the two lines.MS-4 line and a normal line of Caoyuan ON.Iwerw used to seperately cross with a male parental line of alfalfa.The results indicated that the cross significantly reduced the pod production potential in terms of number of pode per plant in the MS-4 line .No difference was found in the number of seeds per pod and the seed weight between the two crosses.It was assumed that the genetic build-up of the MS-4 line may be the main factor capacity of the plant.