بررسي خصوصيات زراعي ژنوتيپ هاي گلرنگ تحت تنش خشكي

چكيده انگليسي :

Evaluation of Agronomic Traits in Safflower Genotypes Grown under Drought Stress Forouzan Bahrami f bahrami@ag iut ac ir Submitted on September 11 2012 Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisor Prof Ahmad Arzani a arzani@cc iut ac irAbstract Drought is one of the most important environmental factors that influences grain yield and quality ofcrop plants in arid and semi arid regions of the world Safflower Carthamus tinctorius L is a drought tolerant species and has been grown in some parts of central Iran for many years To evaluate droughttolerance of safflower genotypes 64 genotypes were grown under non stressed and drought stressconditions using 8 8 simple lattice design in 2011 Agronomic traits and seed quality related traitsincluding days to flowering days to 50 flowering days to maturity plant height primary branches perplant head diameter 1000 seed weight number of head per plant and seed per head biological yield seed yield harvest index and seed oil content oil yield and protein content were measured Results ofanalysis of variance showed that genotype varied significantly for all the studied traits In a way thatdrought stress during seed filling period decreased significantly all the traits with the exception of proteincontent Highly significant and positive correlations were observed between seed yield with 1000 seedweight number of head per plant and biological yield under non stressed conditions Thus in stressconditions there were positive correlation between seed yield and 1000 seed weight number of seed perhead and biological yield Significant and positive correlations were observed between days to flowering days to 50 flowering and days to maturity with plant height under both conditions According tostepwise regression analysis of grain yield the 1000 seed weight and number of head per plant in non stress and 1000 seed weight and number of seed per head in drought stress conditions could explain 63and 55 percent of its variation respectively Path coefficient analysis for grain yield of safflowergenotypes grown under non stressed and stress conditions indicated the positive r 0 62 and r 0 43 respectively direct effects of 1000 seed weight on the yield Cluster analysis could separated thegenotypes into four groups on the basis of agronomic and morphological traits under both conditionsaccording to CCC plot in Euclidean distance of 10 and 15 respectively Group one to four comprised 21 19 5 and 19 genotypes in non stress conditions and 25 24 5 and 10 genotypes in stress conditions respectively Principle component analysis PCA classified the genotypes into three groups under bothconditions The three first component justified 64 and 65 percent of total variation in non stress andstress conditions respectively Among selection indices used stress tolerance index STI and geometricmean productivity GMP were introduced as the superior indices for selection under drought stressconditions Results of principle component analysis PCA and its biplot analysis showed that the twofirst component justified 98 percent of total variation and they were named yield potential and sensitivityto drought stress Based on STI among investigated genotypes IL Kermanshah 47 Hamedan 38 andKordestan 5 were the most tolerant genotypes Moreover these genotypes possessed the highest seedyield under drought stress conditions Thereby can be considered as drought tolerant Key word Safflower Drought stress Seed Yield Oil yield Drought tolerance index

بهرامي، فروزان

بررسي خصوصيات زراعي ژنوتيپ هاي گلرنگ تحت تنش خشكي

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