Race Identification,Genetic Diversity And Evaluation Of Resistance Level Of Different Sunflower Varieties Against Orobanche Cumana Wallr

Sunflower broomrape(Orobanche cumana Wallr.)is a kind of quarantine weed which parasitizes on the root of sunflower.In recent years,it becomes common in sunflower growing area and seriously affects the production and quality of sunflower in China.It heavily restricts the development of sunflower industry.Here with the world-wide used differential host,the physiological race identification of sunflower broomrape from various regions of China was identified;the broomrape-resistant evaluation of sunflower resources was carried out using the dominant race of sunflower broomrape;the genetic diversity of sunflower broomrape was characterized by IS SR markers.The main results are as follows:1.Optimizing the germination condition of sunflower broomrape:our results showed that the optimal germination condition of sunflower broomrape in growth room was:the ratio of loam,vermiculite and nutrient soil was 1:1:1;the proper proportion of seed and matrix was 20mg:500g;the proper temperature was 20?-30?;the suitable soil moisture was 60%-70%.The good permeability and fertility of soil were benefit for the parasitical and rapid growth of sunflower broomrape.2.Physiological race identification of sunflower broomrape:The results showed sunflower broomrape from China belongs to race A,D,E,F and G.Among them,the race G was the highest level of physiological race in China until now.All of our race G sunflower broomrape were from Inner Mongolia(Linhe,Wulateqianqi and Xixiaozhao);race F was only found at Siwangziqi of Inner Mongolia;race E mainly distributed at Xinjiang and Inner Mongolia;the sunflower broomrape of race D was the most,which mainly locates at Xinjiang,Inner Mongolia and Jinlin,race D was the dominant race in our country;race A mainly distributed at Shanxi,Hebei,Shanxi and the Tuzuoji of Inner Mongolia.3.The broomrape-resistant assay was carried out in field.The results showed that in 34 materials of oil sunflower,23 of them such as F08-1 and Kengou 8 were broomrape-immune;6 cultivars such as KY11-46 and Liaofeng F53 were high-broomrape-resistant;PR2302 and S26 were moderate-broomrape-resistant.In 57 materials of confectionary sunflower,4 materials such as JK106 and BC11-1 were broomrape-immune;4 materials such as YK8640 and PR9108 were high-broomrape-resistant;8 materials such as Bakui 138 and Chi 3009 were moderate-broomrape-resistant.Other cultivars were moderate-broomrape-susceptible or high-broomrape-susceptible.4.The broomrape-resistant assay of sunflower was carried out in laboratory using the dominant race of sunflower broomrape(race D).The results showed that the materials of sunflower JK106,Xinkui 23 and BC11-2 as well as other two materials were broomrape-immune;S606,Baikuiza 7,Xinkuiza 7 as well as other 4 materials were high-broomrape-resistant;Bakui 138,Neikuiza 3 as well as other 5 materials were moderate-broomrape-resistant.Similar to the results of field assay,the proportion of high-broomrape-resistant cultivars of oil sunflower is significantly bigger than confectionary sunflower.5.Study on genetic diversity of sunflower broomrape:12 ISSR primers with high polymorphism and good reproducibility were screened out from 100 primers.In addition,the ISSR-PCR reaction system was optimized.Through PCR amplification of 96 samples from different sunflower growing areas in China,a total of 147 bands were detected,of which 90 were polymorphic bands.The percentage of polymorphic bands(PPB)was 61.22%.The results of genetic diversity analysis showed that the Shannon diversity index and Nei's diversity index are different between the various sources of sunflower broomrape population.The Shannon diversity index increased with the increase of number of the sources.Among them,the diversity of sunflower broomrape from Inner Mongolia and Xinjiang was relatively higher.The Shannon diversity index was 0.5560 and 0.5067 respectively.The diversity of sunflower broomrape from Shanxi is low.The results of cluster analysis showed that the sunflower broomrape from 6 different provinces can be divided into two subgroups,of which Shanxi,Shanxi and Hebei provinces were clustered into one subgroup.Jilin,Inner Mongolia and Xinjiang were clustered into another subgroup.The relationship between Shanxi and Hebei was the closest,while Hebei and Xinjiang was the farthest.