ارزيابي صفات زراعي لاين هاي اصلاحي بزرگ در دو شرايط رطوبتي

چكيده انگليسي :

Evaluation of Agronomic Traits in Breeding Lines of Flax under Two Moisture Regimes Zahra Nematallahi zn 808@yahoo com Date of Submission 8 9 2010 Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan 84156 83111 IranDegree M Sc Language FarsiSupervisors s name and Email address Ghodratollah Saeidi gsaeidi@cc iut ac ir AbstractThe oil seed crops are economically very important because of their big contribution in providing theenergy for both human and livestock The increasing of demand for the vegetable oil in the world markethave caused some countries to pay more attention to oilseed production and expanding the researchprograms for these crops Since water deficit stress is an important factor limiting production of the fieldcrops in many areas of the world this study was conducted to evaluate 15 flax genotypes including 10breeding lines along with 5 local populations at two different irrigation regimes based on70 and 140 mmevaporation from Pan class A This research was conducted at the Research Farm of Isfahan Universityof Technology and a randomized complete block design with three replications was used to evaluate thegenotypes in each irrigation regime Result of analysis of variance showed that there were significantdifferences among the genotypes for all of the studied traits except for seed oil content in normalirrigation and days to maturity in limited irrigation regime The results of combined analysis of varianceshowed that the irrigation regime significantly affected on all of the traits with the exception of days to50 flowering Also the interaction between genotypes and irrigation regimes was significant for thetraits of plant height capsules per plant and seed yield The phenotypic correlation coefficients showedthat seed yield had significant and positive correlation with capsules per plant and 100 seed weight in thecondition of limited irrigation However in normal irrigation traits of branches per plant capsules perplant and seeds per capsule highly correlated with seed yield per plot Also ghenetic and phenotypiccoefficient of variations showed that there was genetic variation for agronomic traits among thegenotypes Moreover broad sense heritability was relatively high for days to 50 flowering capsules perplant 100 seed weight seed yield per plant seed yield per plot in both irrigation regimes Therefore itseems that selection can be effective to improve these agronomic traits and to develop drought tolerantgenotypes The results of stepwise regression indicated that in limited irrigation condition number ofcapsules per plant 100 seed weight number of seeds per capsule and number of branches per plantsignificantly contributed in 95 of the variation for seed yield per plant however in normal conditions all these traits except the number of branches per plant entered in the model and contributed in 96 of thevariation for seed yield per plant The results of path analysis for correlation coefficients between seedyield per plant and its components showed that in both irrigation regimes the number of capsules perplant had the highest direct and positive effect and also indirect effects via the other yield components onseed yield per plant Generally the results of this study showed that in both soil moisture conditions thenumber of capsules per plant can be considered as an appropriate selection criterion in breeding programsof flax to improve seed yield In clustering of genotypes based on the studied traits all genotypes wereclassified in three and two separate groups in normal and limited irrigation respectively Using differentwater stress indices SSI STI TOL GMP and MP revealed that STI seems to be the most suitable indexfor recognizing more tolerant genotypes to drought conditions and based on this index local populationof Chaharmahal was the most tolerant oneKey Words Flax Moisture regimes Seed yield and yield components Drought stresstolerance index

نعمت اللهي، زهرا

ارزيابي صفات زراعي لاين هاي اصلاحي بزرگ در دو شرايط رطوبتي

بزرك , رژيم رطوبتي , عملكرد دانه و اجزاي آن , شاخص هاي تحمل به تنش خشكي