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1. *"1' .--j/) ' *-'*1 /.,/ 'i -"\ Journalof Cerealsand OilseedsVol. 2(2),pp. 32-37 February2011 Availableonline at http://www.academicjournals.org/jco ISSN-21 -6575@201 AcademicJournals 41 1 Full LengthResearchPaper A study of morphological basis sf corn (Zeamays L.') yield underdroughtstressconditionusingcorrelation and path coefficientanalysis Khodadad Mostafavi3*,Mohammad Maryam Ashofteh Beiragil, Mohsen Ebrahimi2, Golbashya,Saied Khavari Khorasanis lDepartmentAgronomy Plant of and Breeding, College Agriculture,Zabol of University, Zabol, lran. 'Department Agronomy^& Breeding- of Plant College AbouraihanUniversity Tehran, of - of lran. 'lslamic AzadUniversity- KarajBranch lran. aNanoBioTechnology- University Tehran of lran. sScientific membrane khorasan-Razavi of Agricultural Research Natural and Resources Center Mashhad, lran. Accepted 25 February,201 1 In order to study the morphological basis of corn yield under normal irrigation and drought stress condition,an experimentwas carried out on basis of completerandomized block design with three replicationsand 28 new hybrids of corn; in addition6 commercialhybrid (as control) under normal irrigation ?nd drought stress condition in Khorasan Razavi Agricultural Research and Natural Resources Center,Mashhad, and phenotypic lran on 2009.Genotypic and path correlation coefficients coefficientswere estimatedto determinethe associationand direct and indirect effects of different characters total yield. Resultsof analysisof variance(ANOVA) on showedthat in both conditionsthere were significantdifferencesbetweenall hybrids for all traits. In normal irrigationcondition KSC500 hybrid and in stress condition N-l1 hybrid was better than others in grain yield trait. Under stress condition,number of kernelsper row had the highestcorrelation with grain yield, while under normal irrigationear diameterhad the highest correlationwith grain yield. Accordingto this study, kernel No./earis more closely and significantly relatedwith total yield. This emphasized that selectionbased on the characters which enhancekernelnumberper ear will be moreeffectivein improvingyield under droughtstresscondition. phenotypic Key words: Cornhybrids, genotypic correlation, correlation, drought stress, irrigation. INTRODUCTION lran is very muchless in yielddue to drought permanent stressat production many constraint agricultural to in pollination stage,which leadsto pollendesiccation and developing countries, an occasional and causeof losses seed setting.Among variousabioticand biotic stress production developed of agricultural in ones (Ceccarelli factors, drought stress an important is cause genotype for and Grando, The best optionfor crop production, 1996). by environment interactions maize across years, in yieldimprovement yieldstability and underdrought stress locations (Loffleret al., 2005) and most likely within conditions to develop is droughttolerant crop varieties. individual (Bruce al.,2002). fields et One of the maingoalsin breeding programs selection is Droughtis one of the most important of the best genotypes abioticstress under droughtstressconditions factors(Bruceet al., 2002),whichaffects almostevery (Richardset af, 2002). However,low heritability of aspects plantgrowth (Aslam al.,2006). of et Drought a is drought tolerance and lack of effective selection approaches development resistant limit of crop cultivars to environmental stress(Kirigwiet al., 2004).Several reportsof physiological, morphological and molecular .Conesponding author. E-mail: mostafavi@kiau.ac.ir. Tel: traitshave'been suggested improving drought for the and 0098936568661 0. salinity tolerance crops of that many of them potentially