بررسي سازگاري و تحمل به خشكي ارقام كلزا

چكيده انگليسي :

Adaptability and drought tolerance of canola cultivars in Isfahan Mohsen jafarzadeh M9jafarzadeh@yahoo com Date of submission 31 10 2010 Department of Agronomy and Plant Breeding Isfahan University of Technology Isfahan 84156 83111 Iran Degree M Sc Language Farsi Supervisors s name and Email address Mohammad Mahdi Majidi majidi@cc iut ac ir Abstract This study was conducted to assess the adaptation and tolerance to drought stress in different canola cultivars using agro morphological and phenological traits The experiment was conducted at Isfahan University of Technology Research Farm in 2008 09 The 28 canola cultivars used were subjected to water stress and compared to a normal irrigation condition implementing two separate randomized complete block designs experiments Fisher and Murrer Stress Sensitivity Index SSI Tolerance Index Tol Rosille and Hemblin Mean Productivity MP Geometric Mean Productivity GMP and Fernandez Stress Tolerance Index STI were used to compare reactions of genotypes in the two moisture conditions Results showed that drought stress reduced variation for most traits studied Under both moisture conditions coefficient of genetic variability for proline and chlorophyll content was highest and lowest for days to heading It was revealed that drought stress significantly increased proline content while decreased grain yield yield components and other traits Results of analysis of variance showed that there was a significant difference in canola cultivars for all measured traits except that of chlorophyll a b ratio Based on mean comparison in both stress and non stress conditions cultivar NK fair had the highest grain yield Under normal irrigation the highest percentage of oil content belonged to cultivar RPC 2023 while under water stress condition NK bravour was superior for this trait Presence of significant genotype by environment interaction for some traits implied different reactions of cultivars to normal and water stress conditions Results showed that proline content had significant correlation with grain yield under drought stress and possibly can be used as an indirect selection index for drought tolerance Based on correlation of tolerance indices with the grain yield under both moisture environments the STI GMP and MP were identified most appropriate in selecting for drought tolerance genotypes Mean comparison of tolerance and sensitivity indices for canola cultivars showed that based on STI index NK fair cultivar was the most tolerance and RPC 2023 was the most sensitive cultivar under drought condition Based on biplot results of indices NK fair and NK bravour may be introduced for cultivation under drought stress conditions since they had higher yield potential and lower sensitivity to drought condition compared to other genotypes Stepwise regression result revealed that number of grains in pod number of pod per unit area and 1000 grain weight had the greatest contribution in justifying grain yield under non stress condition Under drought condition 1000 grain weight number of pods per plant number of grain per pod and days to heading had the greatest contribution Factor analysis for both normal and drought stress conditions revealed six hidden factors justifying 85 of all variations under normal and 82 under drought stress conditions respectively Under non stress condition these factors were composed of yield production of pod metabolite compounds pod factor grade one photosynthesis and grade two photosynthesis respectively Under water stress condition factors included yield potential pod production grain characteristic phenological factor and grain nutrition components respectively Cluster analysis results based on morphological and physiological traits under non stress and stress conditions divided cultivars into three groups Cultivars which had the most genetic distance could be used as an appropriate candidate for breeding programs to improve and produce new cultivars with higher drought tole

جعفر زاده قهدريجاني، محسن

بررسي سازگاري و تحمل به خشكي ارقام كلزا

شاخص تحمل , عملكرد دانه , عملكرد روغن , همبستگي , تحليل عاملي و تجزيه خوشه اي