Resistance Of 28 Chinese Wheat Mini-core Collections To Puccinia Triticina

Leaf rust of wheat caused by Puccinia triticina Eriks is one of most the important and widespread disease on wheat, which is adapted to a wide range of climates, occurs wherever wheat is grown, and can cause significant yield and economic losses. Given favorable conditions, the disease can cause yield losses of up to 40%. Application of resistant cultivars is considered as the most economical, environment-friendly, and effective way to control this disease. Wheat (Triticum aestivum L.) core collections act as an important germplasm resource for resistance breeding to leaf rust in China, which is better materials to research and use the rich germplasm resource. To evaluate the leaf rust resistance of Chinese wheat mini-core collections, we chose 28 accessions with a wide range of leaf rust reaction (R, SR, MS and S) and 39 near isogenic lines (NIL)or single gene lines in thatcher background with known leaf rust resistance genes as testers for resistance analysis to leaf rust. The following results were obtained.1. Eight pathotypes of P. triticina were inoculated on 39 NILs and 28 accessions for evaluating their resistance in seedling stage and gene postulation. The results showed that Lr14a, Lr2b, Lr17, Lr33, Lr16, Lr11, Lr3bg, Lr10, Lr36 and Lr20 probably present in the test lines. Of them, Honghuazao may have Lr14a and Lr2b. Xinkehan 9 probably contain Lr17, Lr2b, Lr14a and Lr33. Orofen probably contains Lr16, Lr11, Lr10, Lr3bg, Lr20 and Lr33. Xinyi 4 may have Lr36. Zipi may have Lr2b.2. The tested materials have excellet resistance to leaf rust in adult stage. Among the lines, Bihongsui, Xiaobaimai, Xiaohongpi, Dingxingzhai, Honglidangnianlao, Laomai, Jiangxizao, Honghuazao, Chanbuzhi, Sumai 3, Chejianzi, Paozimai, Gansu96, Sanyuehuang, Fuyanghong, Jiangmai and Zipi are belong to slow rusting type, which are 61% of tested genotypes. Zhongyou 9507, Dunhuachunmai, Xinkehan 9, Orofen, Xingyi 4, Chengduguangtou and Hongdongmai are nearly immune to the leaf rust pathogens, which are 25% of tested material. Dabaipi and Youmangsaogudan are moderately susceptible, which are 7% of tested material. 7% of tested materials such as Villa Gloria and Hongmangzi are susceptible to leaf rust pathogens.3. Twenty molecular markers closely linked or co-segregated with Lr1, Lr9, Lr10, Lr19, Lr20, Lr21, Lr24, Lr26, Lr28, Lr29, Lr34, Lr35, Lr37, Lr38 and Lr47 were employed to process molecular marker-assisted selection (MAS). The specific fragments of Lr1, Lr10, Lr26, Lr28, Lr34 and Lr37 were amplified in the test genotypes. However, the others had no aimed products.4. The resistance analysis synthetically indicated that Xinkehan 9 probably has Lr17, Lr2b, Lr14a and Lr33. Xingyi 4 probably has Lr26, Lr36 and Lr37. Zipi probably contains Lr2b and Lr34. Dabaipi probably contains Lr1. Bihongsui probably contains Lr1, Lr10 and Lr34. Zhongyou 9507 probably contains Lr10. Xiaobaimai, Honglidangnianlao, Laomai, Chanbuzhi, Sumai 3 and Chejianzi probably contain Lr1 and Lr34. Honghuazao probably contains Lr1, Lr34, Lr14a and Lr2b. Jiangxizao, Paozimai, Sanyuehuang, Youmang saogudan, Fuyanghong, Chengduguangtou and Jiangmai probably have Lr34. Dunhua chunmai and Gansu 96 probably have Lr28. Orofen probably contains Lr34, Lr16, Lr11, Lr3bg and Lr33. While Xiaohongpi, Dingxingzhai, Hongli Dangnianlao, Zhongyou 9507, Honghuazao, Dunhuachunmai, Xinkehan 9, Orofen, Gansu 96, Youmang Saogudan, Xingyi 4, Chengdu Guangtou and Hongdongmai may also carry unknown resistance genes to leaf rust. Lr9, Lr19, Lr20, Lr21, Lr24, Lr29, Lr35, Lr38 and Lr47 are not existed in the tested lines.The results show that the wheat mini-core collections have good leaf rust resistance and contain rich leaf rust resistance genes, and they can be as resistance resource for resistance breeding. The results are also theortical accordance for reasonable gene placement and foundation of further reseaching of wheat mini-core collections.