بررسي ارتباط بين صفات بذري و علوفه‌اي و گزينش ژنوتيپ‌هاي متحمل به خشكي در دو گونه‌ي Bromus inermis و Dactylis glomerata

چكيده انگليسي :

116 Relationship between Seed and Forage Characteristics and Selection for Drought Tolerant in Bromus inermis and Dactylis glomerata Genotypes Arezoo Sharifi arezoo2051@gmail com December 26 2016 Department of Agronomy and Plant Breeding Isfahan University of Technolog Isfahan 84156 8311 IranDegree M Sc Language FarsiSupervisor Mohammad Mahdi Majidi m majidi@cc iut ac irAbstractOrchardgrass Dactylis glomerata and smooth bromegrass Bromus inermis belong to large family ofgramineae have high compatibility to different climates Drought stress is the most common type of stressthat reduces plant growth This research was conducted to assess replicationship between seed and forageyield and evaluate drought tolerance in these two species at research farm of Isfahan University ofTechnology located at Lavark during 2015 For this purpose 36 genotypes from each species wereevaluated according a randomized complete block design with 4 replication under normal and droughtstress moisture environments In orchardgrass the results indicated that drought stress significantlyaffected most of measured traits especially seed yield and forage yield The highest genotypic coefficientof variation GCV under normal condition was observed for number of seed per plant 42 24 and underwater stress condition it was observed for seed yield 41 66 The maximum and minimum broad senseheritability in normal condition was observed for days to ear emergence 83 95 and percent of dry matteryield 2 6 39 respectively In drought stress condition the highest and minimum broad sense heritabilitycalculated for days to ear emergence 86 14 and crown width 6 27 respectively According to the bi plot of seed yield and forage yield in normal condition genotypes 32 13 21 8 and 2 and under droughtstress condition genotypes 32 35 13 and 22 showed higher seed yield and forage yield Results of linearregression analysis between seed yield and dry matter yield indicated a significant correlation betweenthese two traits in normal condition while in stress condition no correlation was observed According tostepwise regression analysis in normal condition the number of panicle seed weight in ear days toflowering number of seeds per panicle justified the majority of seed yield variation Under drought stresscondition the number of seed in plant 1000 seed weight harvest index width of flag leaf were the mostcomponents of seed yield Genotypes 32 33 and 13 were identified as the most tolerant genotypesaccording to stress tolerance index STI In smooth bromegrass the results showed the significant effectsof drought stress on most of the measured traits The highest GCV under normal condition was observedfor number of seed per plant 87 52 and under stress condition it was observed for seed yield 76 12 The highest broad sense heritability under normal condition was observed for days to flowering 90 84 and the minimum broad sense heritability was observed for percent of dry matter yield 3 30 28 According to bi plot of seed yield and forage yield in normal condition genotypes 27 23 26 35 and 6 showed higher seed yield and dry forage yield Significant correlation was found between these two traitsin normal condition while no correlation was observed in stress condition Results of stepwise regressionanalysis showed 95 percent of seed yield was explained by number of seed per plant 1000 seed weight harvest index length of flag leaf width of flag leaf under normal condition and 97 percent of thevariation justified by seed weight in ear number of seeds in plant number of seeds per panicle harvestindex days to flowering under stress condition Based on stress tolerance index STI genotype 27 wasthe most tolerant in this species Results indicated that would be possible to find genotypes with highforage and seed yield in Orchard grass and smooth bromegrass Keywords orchardgrass smooth bromegrass Drought stress Forage yield seed yield

شريفي گرمدره، آرزو

بررسي ارتباط بين صفات بذري و علوفه‌اي و گزينش ژنوتيپ‌هاي متحمل به خشكي در دو گونه‌ي Bromus inermis و Dactylis glomerata

علف باغ , علف پشمكي , تنش خشكي , عملكرد علوفه , عملكرد بذر