Screening Of The Host Range Of Orobanche Cumana And Study On The Resistance Mechanism Of Helianthus Annuus To O.Cumana

Objective: To clarify the host range of Orobanche cumana seeds in different regions of Xinjiang,and to provide a basis for the use of agricultural control measures to prevent O.cumana seeds.By evaluating the resistance levels of different resistant sunflower varieties(lines)to O.cumana,and then measuring the biomass and physiological and biochemical effects of two different resistant sunflower varieties after O.cumana infection and the effect of differential gene expression.Analyze the physiological,biochemical and molecular mechanisms of sunflower resistance to O.cumana,and provide references for Xinjiang sunflower resistance to parasitism breeding and control measures.Method: The O.cumana seeds collected from four regions in Xinjiang were co-cultivated with 21 species of 9 families and 21 species by using the pot experiment,and the host range of O.cumana in the four regions was judged based on the parasitic rate on the root systems of different host plants;the pot and root chamber mexperiments were used to evaluate the resistance level of 13 sunflower varieties grown in Xinjiang,and two sunflower varieties with obvious resistance differences were inoculated with O.cumana to evaluate the effects of O.cumana on the biomass and physiology and biochemistry of different resistant host varieties;At the same time,take samples at different parasitic stages of O.cumana for transcriptome sequencing to analyze the differential gene expression of different resistant sunflower varieties after inoculation of O.cumana.Result:1.There is little difference in the host range of O.cumana in the four regions.They main parasitize such crops of Asteraceae,Solanaceae and cucurbita as sunflower,safflower,tomato,and tobacco,and the parasitic rate is 100%;Carrots also can be parasitic,and the parasitic rate is 25%.The O.cumana of Regiment 168 Division No.4 and Regiment 182 Division No.5 can also parasitize gourd melons,with a parasitic rate of 50%.The O.cumana of Shihezi University experimental farm and Beibeiwan Town,Qitai County can also parasitize pumpkins,with a parasitic rate of 25% and the latter can also parasitize celery(50%).O.cumana in the four regions does not parasitize peppers,eggplants,cucumbers,onions,corn,wheat,beets,soybeans,peas,broad beans,lentils and flax.In addition,two wild hosts of O.cumana,Karelinia caspia(Pall.)Less and Cirsium arvense were found and identified.2.One high-resistant material Tonghui 31,one resistant material 17SPKS9XKS1,and 11high-sensitivity materials were selected from 13 sunflower varieties(lines).There was no significant difference in plant morphology,fresh dry weight of roots,stems and leaves,root-to-shoot ratio and other biomass distributions of the selected resistant variety Tonghui 31 after inoculation of O.cumana compared with the control;Guan er No.361,a sensitive variety compared with the control,the fresh weight of roots,stems and leaves decreased by 49.94%,43.59%,and 44.90%,the plant height decreased by 58.09%,and other indicators also decreased significantly after inoculation with O.cumana.3.Regardless of whether the O.cumana is inoculated or not and the time after inoculation,the content and activity of physiological and biochemical indexes in the plant are almost root>leaf>stem.When O.cumana were inoculated for 7 days,the contents of ROS,MDA,etc.and the activities of protective enzymes such as POD were not greatly affected.However,when O.cumana were inoculated for 24 days,the above indicators were almost unaffected in the control group,but the treatment group changed significantly,and the range of change is generally root>leaf>stem.4.A total of 655.9Mb clean reads were obtained by transcriptome sequencing of O.cumana,Q30 was greater than 93.79%,GC content was 43.92%～45.29%,and the host sunflower root system obtained a total of 1164.8Mb clean reads,Q30 was greater than94.00%,GC The content ranges from 43.73% to 44.79%.A total of 655.9Mb clean reads were obtained by transcriptome sequencing,with Q30 greater than 93.79% and GC content between 43.92% and 45.29%.A total of 1164.8Mb clean reads were obtained from host sunflower roots,with Q30 greater than 94.00% and GC content between 43.73% and 44.79%.At 7 days after inoculation,GO function analysis on the differential genes in the root system of resistant sunflower cultivar shows that the differential genes were mainly involved in ion binding process(22).KEGG enrichment analysis showed that the differential genes were mainly involved in spliceosome(3)and protein processing endoplasmic reticulum(3)metabolic pathways.The GO function analysis of the different genes in the root system of the sensible varietiy shows that the different genes were mainly involved in the process of hydrolyzing O-glycosyl compounds(4),and the KEGG enrichment analysis shows that the different genes were mainly involved in butanoate metabolism(2).At this time,a total of two potential resistance genes were screened: Hsp7 c and CHI1.At 24 days after inoculation,GO function analysis on the differentially expressed genes in the root system of resistant sunflower cultivar shows that the different genes were mainly involved in the biological process(186),and KEGG enrichment analysis shows that the different genes were mainly involved in protein processing endoplasmic reticulum(28).The GO function analysis of different genes in the root system of sensible variety shows that different genes were mainly involved in the biological process process(2424),and KEGG enrichment analysis shows that different genes were mainly involved in the metabolic pathway(387).At this time,a total of21 potential resistance genes were screened: C7A22,XTR8,FADX,LOX21,THIC,HMGB3,ATPAO4,DRP5 A,CASP1,RNLX,CATA1,Ph R1,KSL7,MDL2,C71 DA,NRAT1,NIP21,STC,CSSPLC,PLDP2 and ATMRP9.q RT-PCR analysis identified 6 potential resistance genes:PPCK1,ATTERF-1,ATHSP 22.0,TPS2,NCED1 and RADL3.