بررسي ميزان خودگشني و دگر گشني در گياهان حاوي اندوفايت و بدون اندوفايت فسكيوي بلند

چكيده انگليسي :

56 Seed Production through Self and Cross pollination in endophyte infected and non infected tall fescue Festuca arundinacea Maryam davoudi davoudi maryam@yahoo com Supervisor Mohammad R Sabzalian Assist Professor Aghafakhr Mirlohi Prof Abstract Seed set through self pollination as the most important reproduction system plays important role inmaintaining plants genotype and generating uniform plants in tall fescue Festuca arundinaceae which is widelyused as fodder and lawn On the other hand tall fescue has symbiosis association with endophytic fungus Neotyphodium coenophialium improving forage and seed yield and protecting plants against pests and diseases Any change in plant genotypes due to cross pollination may decrease the effect of endophytic fungi The presentexperiment aimed to evaluate the rate of self and cross pollination in different genotypes as well as the effect ofendophytic fungus on self and cross pollination Genetic material for the present research included eleven fectucagenotypes along with six genotypes native to Iran arranged in a complete block design with three replications Nine panicles from each genotype were placed in paper pockets before flowering and compulsive self pollinationwas applied Others plant panicles were left to be open pollinated Also peduncle length leaf flag area plantdiameter the number of panicles fresh weight leaf greenness percent of pollen grains alive the number of seedsin self pollinated panicle number of seeds in cross pollinated panicle self pollination percent 100 seed weightdue to self pollination 100 seed weight due to cross pollination and the ratio of seed numbers from self pollinatedpanicle to seed numbers from cross pollinated panicle were evaluated Results showed that morphological traitsincluding the number of seeds per self pollinated panicle and number of seeds in cross pollinated panicle had highgenetic variation coefficient implying that they are less affected by environment Results from mean comparisonsshowed that among studied genotypes two exotic genotypes of Jaguar2 Silverado and three Iranian genotypeshad self pollination percentage of 66 16 58 1 and 58 93 respectively Genotype Monarch exhibited the highestpercent of seed set due to cross pollination These results denoted that it is possible to produce seeds due to self pollination and subsequently pure lines in exotic and endemic tall fescues genotypes Factor analysis showed thatfirst two factors account for 85 of variations among traits The first factor accounted for 80 of traits varianceand had substantial contribution due to factor coefficients of number of seeds in self pollinated panicle number ofseeds in cross pollinated panicle 100 seed weight due to self pollination and the ratio of seed numbers from self pollinated panicle to seed numbers from cross pollinated panicle Hence this factor was called sellfing seed sink The second factor accounted for 5 of variance having highest contributions due to factor coefficients for theplant diameter fresh weight and plant length and was nominated as yield factor In order to evaluate the effect ofendophyte fungus on self pollination and cross pollination rates two genotypes infected with endopyhte and theirnoninfected counterparts were used Data were analysed using a 2 2 factorial test Analysis of variance resultsshowed that genotypes endophyte interaction was significant in traits of fresh weight leaf flag greenness thenumber of seeds in cross pollinated panicle and the percent of seed set due to self pollination Results of meancomparison indicated that endophyte infection could increase seed set through self and cross pollination in tallfescue Presumably this may results from changes in hormone balances induced by endophyte fungus which inturn may improve plant seed and forage yield Keyword cross pollination endophyte tall fescue self pollination

داودي، مريم

بررسي ميزان خودگشني و دگر گشني در گياهان حاوي اندوفايت و بدون اندوفايت فسكيوي بلند