Breeding Research In Maize Head Smut By Marker-assisted Selection

According to Ministry of Agriculture latest statistics, corn is the grain and economic crops that has been planted on a wide range, but Maize head smut is one of the maize disease that is the greatest factor to cause production to reduce in spring maize area of china. Since 19 century, through sensitive cultivar were planted, maize head smut become heaviest year by year. For a long time, breeders discover the most effective way to control maize head smut is breeding resistance cultivar.Cooperation with Xu Mingliang of National maize improvement center, China Agricultural Univercity. As Xu's identification and mapping research about major resistance QTL of maize head smut to be the foundation. Due to Jing24 is sensitive cultivar. So we get the markers close linked with major resistant QTL to improve it. As the resistant inbred line Ji1037 to be donor parent, the sensitive inbred line Jing24 to be the recurrent parent. Through hybridization and backcross, we transfer the major resistance QTL from Ji1037 to Jing24, in order to let Jing24 has resistance trait. Using marker assisted selection to ensure major QTL within the selected plants and shorten breeding program.Using Ji1037, Jing24 and inoculated BC2 generation individual population to be foundation material. Finally, we selected amplified well and diverse in backcross parents primers MZAI and 661, that locate on upper and down stream in resistance major QTL.The primer information may involved in background selection inquired on www.maizegb.org,73 pairs primers after designed by our lab again, we got amplified well, covered ten chromosome evenly and suited to as basic primers group in any of improment population. Then the fluorescence primers were syntheses by ABI and yingjun in Shanghai. Finally,73 pair background candidate primers are selected by Ji1037 and Jing24, and 45 pair primers are acquired which were distinctive between backcross parents. Backgcross population is set in foreground selection and background selection generation by generation,10 plants are get into next round selection which foreground selection behavior is close linked to target resistince gene as well as restoration rate of background was highest, BC2 were identified by inoculated. At last, we get 23 BC3 generation plantlets that restoration rate is more than 96%, and then inbreds these plantlets.