Effect of agronomic traits and drought resistance indices on determination of susceptible and tolerant sunflower lines

Subject Areas : Crop Production Research

babak maghsodi damavandi ¹ , shahram lak ² , mahdi ghafari ³ , mojtaba alavi fazel ⁴ , tayeb saki nezhad ⁵

1 - دانشجوی دکتری، گروه زراعت، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران
2 - گروه زراعت، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران
3 - مؤسسه تحقیقات اصلاح و تهیه نهال و بذر، سازمان تحقیقات، آموزش و ترویج کشاورزی، کرج، ایران
4 - گروه زراعت، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران
5 - گروه زراعت، واحد اهواز، دانشگاه آزاد اسلامی، اهواز، ایران

Received: 2019-09-03 Accepted : 2020-01-23 Published : 2020-02-29

Keywords: Correlation, Drought stress, Sunflower, Dendrograms Cluster, Susceptible and tolerant line,

Abstract :

 In order to determine the susceptible and tolerant lines of sunflower to drought stress, acompletely randomized block design with three replications was conducted at Karaj seed OilResearch Institute. In this study, 12 different sunflower lines have been identified for thecharacteristics related to drought tolerance and were selected two susceptible and tolerantlines. Initially, sunflower lines were cultivated in two separate experiments under normalirrigation and drought stress conditions. Drought stress was carried out through stop irrigationin step 2 to 8 leaves formation. The studied traits included agronomic characteristics anddrought stress indices of sunflower, such as Plant height, Stem diameter, Head diameter, Seedyield, Leaf Area Index, Relative Water Content, SSI and STI. The studied traits weresignificantly different in water stress, except stem diameter. After analyzing the tested factorsand analyzing the data, the results were obtained by analyzing the percentage of variation ofstudied traits, calculating stress indices (drought tolerance indices, drought sensitivity) anddendrogram drawing from Cluster analysis of cultivars was identified. According to theresults, in terms of water deficit stress, RGK26 and RGK41 produced the highest and thelowest seed yield per plant. Comparison of traits can identify BGK221 as susceptible line andRGK46 as tolerant line among 12 studied lines. Also, correlation between traits showed thatdrought tolerance index (STI) was positively correlated with almost all traits. In addition,grain yield was positively correlated with all traits except plant height.