Selection, Pyramiding And Genetic Analysis Of Stripe Rust Resistance By Rapd Markers In Wheat

Wheat Stripe Rust is one of three widely spread diseases for crop production in China, and to breeding resistant cultivars offers an effective and economical way to control the disease occurrence and spreading,however, due to its single resistant gene,the resistance to Stripe Rust in most wheat cultivars dispeared after years of cultivati- on. Therefore, selecting and pyramidingthe resistant gene for the Differential Hosts of Wheat Stripe Rust to constitute a new endurance instead of pyramiding of multiple genes indicated a new way for study and application of wheat stripe rust. Our study was focus on selecting and pyramiding different resistant genes for theDifferential Hosts of Wheat Stripe Rust. New wheat cultivars would be bred through pyramiding. And hybrid doubled wheat were studied by RAPD technique, also the an- alysis of the important agronomic characters and cluster was conducted.The results sh- owed as follows:1. The resistance to some major epidemic races in wheat stripe rust at adult stag-e, namely CY31, CY32 and Su14 was studied. 11 varieties, such as Wanmai369,N9209,AR63,Shannong980098,Xinong957,212,Chunnong142,WT4,WT6,WT300 and WT400 exhibited more than one resistance to epidemic Differential Hosts of Wheat Stripe Rust; and 29 varieties such as Shanyou302,Zhongyou9507,WT600 and WT105 resistance to epidemic Differential Hosts of Wheat Stripe Rust were selected.2. To study on agronomic characters of the Doubled hyploid varieties, 82 Double-d hyploid varieties was bred by confecting different hybrid combination such as (888-5×Qianjinzao)×Tike102,(888-5×Tike102)×Qianjinzao and(Tike102×Qianjinzao)×888-5, after anther cluster on the second generation and chromosome doubling. The result sh-owed that: The variation and variation range of this low-stem, early-maturing and highhundred seed weight Hybrid Doubled varieties were big. Their plant hight increased, their spike length, spikelets number, kernel number and hundred seed weight increased.3. The resistance of the Hybrid Doubled varieties at adult stage, CY31, CY32 and Su14was identified and selected. The results showed that 31 Doubled hyploid varieties sho-wed more than one resistance to Differential Hosts of Wheat Stripe Rust,with the pe- rcentage 23.17%; 6 Hybrid Doubled varieties were both resistant to CY31 and CY32, the percentage 7.32%; 5 Hybrid Doubled varieties resistant to CY31, and Su14,the percentage 6.10%; 1 Hybrid Doubled varieties resistant to CY32 and Su14,the percen-ttage1.22%, none of these varieties were resistant to all of them.4. RAPD Analysis of the varieties resistant to CY32 showed that 1 additional DNA fragment amplified repeat and steadily in resistant gene pool and resistant parentHuayu888-5 by the primer S20 was about 670bp,it can be used for molecular marker assisted breeding.5. Using genetic diversity by combination of traditional morphologic and RAPD markers, 79 stripe rust resistant varieties were evaluated. The characters of these varie-ties included low plant height, long spike length, hight kernel number and hight hund-red seed weight. The variation based diversity index was: hundred seed weight>spike length>kernel number>populationdensity>plant height>spikelets length>effective tiller.Thecoffection of varieties of 7 agronomic characters between 12.96% and 38.17%, the di-versity index ranged from 1.7365 to 2.0461.The genetic diversity of agronomic charac-ters is rich.6.The genetic diversity among 79 stripe rust-resistan t wheat varieties was inves-tigated by using 300 RAPD markers. A total of 119 alleles had been identified in th-ese varieties by 11 RAPD primers. The genetic polymorphism site proportion is 99.09%.The mean GS was 0.7281, and the mean GD was 0.3238. Based on the GD, they could be divided into three categories, the close relationship clustered together, throughpolymerization of multiple genes for resistance to rust DH materials are clustered to-gether with other new anti-genetic material distant relations, Rust resistance is the new type. The experiment showed that RAPD analysis could reveal genetic difference and category of varieties.The results also indicated RAPD analysis better reveal the geneticmaterial differences and could reflect the genetic relationship among different materials.