Scab Resisitance Improvement Of A New Waxy Wheat Line 4446 With High Yield

High quality,disease and insect resistance and high yield are the three goals of wheat breeding.Scab is a major wheat disease in the middle and lower reaches of the Yangtze River,commonly known as wheat"cancer".Wheat varieties with no resistance to scab will not only reduce yield,but also produce don toxin which is harmful to human and livestock.4446 is a new waxy wheat line with high yield introduced in our laboratory.This study aimed to introduce the major QTL for scab resistance into 4446 by means of molecular marker assisted method combined with prospect and phenotypic selection.In this study,nmas022,a major QTL for Scab Resistance Fhb1,Fhb2,Fhb4 and Fhb5,was used as the donor parent,and 4446,a waxy wheat line with high yield,was used as the recipient parent,two near isogenic lines 4446-3B6Bb5A(4446+Fhb1+Fhb2+Fhb5)and 4446-3B4B5A(4446+Fhb1+Fhb4+Fhb5)carrying multiple QTL combinations for scab resistance were obtained.Compared with recurrent parents,the number of diseased spikelets decreased by 86%,the length of diseased axis decreased by79.3%and 93.9%,and the resistance to infection increased by 79.4%and48.1%,respectively.There was no significant difference between the two lines and their recurrent parents in flowering period,plant height and grain number per spike.The average tiller number of the two near isogenic lines was significantly higher than that of the recurrent parents,and the 1000 grain weight had no significant change compared with the recurrent parents;The yield of 0.5m~2plot of 4446-Fhb1+Fhb2+Fhb5 was significantly higher than that of its recurrent parents.Through marker assisted selection,the QTL for scab resistance was introduced into 4446,and the high-yield waxy wheat with scab resistance was obtained,which had no significant difference with recurrent parents or higher yield than recurrent parents.