Variation of Leaf Pubescence Status and Its Association with Resistance to Bean Pyralid(Lamprosema indicata Fabricius)in Soybean

It was found that the pubescence status on leaf blades was different from that on leaf petioles.According to a survey on 392 cultivars from all the six eco-regions of soybeans in China,the status of pubescence on leaf blade was classified as prostrate,semi-prostrate and skewed and that on leaf petiole as appressed,semi-appressed and erect.It was found that the ratio of skewed leaf blade pubescence and erect leaf petiole pubescence increased along with the increase of geographic latitude,indicating the status of leaf pubescence being related with their geographic sources.Significant correlations were detected between status of leaf blade pubescence and that of leaf petiole pubescence,between status of leaf blade pubescence and resistance to bean pyralid(Lamprosema indicate),and between status of leaf petiole and resistance to bean pyralid,with χ2 values as 164.72,187.46 and 123.44,respectively.There showed significant differences of percentage of rolled leaves(PRL)and number of rolled leaves(NRL)between different leaf blade and petiole pubescence types.The PRL of prostrate and semi-prostrate leaf blade pubescence were 51.37% and 6.98% lower than,while those of NRL were 32.25% and 3.72% lower than the skewed leaf blade pubescence,respectively.The PRL of appressed and semi-appressed leaf petiole pubescence were 42.20% and 62.81% lower than,while those of NRL were 25.93% and 46.40% lower than the erect leaf petiole pubescence,respectively.Therefore,the results showed both the leaf blade pubescence type and the leaf petiole pubescence type can be used as the indicators of resistance to bean pyralid in germpasm evaluation and breeding programs.