ارزيابي تنوع ژنتيكي و وراثت¬پذيري صفات كمّي در ژنوتيپ¬هاي نخودتيپ كابلي در شرايط ديم

Assessment of genetic diversity and heritability of quantitative characters in Kabuli type chickpea germplasms under dryland conditions

دانه گیاه نخود (Cicer arietinum L.)حاوی منبع مهم پروتئین بوده و نقش بارزی در رژیم غذایی انسان دارد. از این¬رو آگاهی از روابط بین عملكرد و اجزای عملكرد در برنامه¬های به¬نژادی نخود بسیار مهم و ضروری می-باشد. مطالعه حاضر به¬منظور ارزیابی معیارهای عملكرد در نخود با‌استفاده از تجزیه خوشه‌ای، تجزیه بهعامل¬ها و برآورد وراثت‌پذیری صفات انجام گردید. این مطالعه با‌استفاده از 13ژنوتیپ نخود در ایستگاه مركزتحقیقات كشاورزی و منابع‌طبیعی خرم‌آباد واقع درسراب چنگایی در قالب طرح بلوك¬های كاملتصادفی با 4 تكرار درسال زراعی 1393-1392 اجرا گردید. ژنوتیپ¬ها شامل 11ژرم‌پلاسم و دو رقم اصلاح‌شده و محلی (آزاد و شاهد محلی گریت) بودند. صفات كمّی اندازه¬گیری‌شده طبق پارامترهای آماری تجزیه و تحلیل گردیدكه در این راستا تجزیه واریانس نشان داد كه صفاتارتفاع از اولین‌غلاف و تعداد غلاف پوك در بوته بیشترینتنوع رادارند.تجزیهبه‌عامل¬ها،19صفتزراعی را به چهارمؤلفةاصلی تفكیك نمودندكهمجموعأ72/78درصد از كل تغییرات در شرایط دیم را شامل می¬شدند؛ به¬گونه¬ایكه عامل اول، دوم، سوم و چهارم به‌ترتیب 06/39‌درصد، 1/18‌درصد، 21/13‌درصد و 33/8‌درصد از كل تغییرات را به‌خود اختصاص دادند.از طرف دیگرتجزیةخوشه¬ایبه‌روش فاصله اقلیدسی،ژنوتیپ¬هارا بر اساس صفات مذكور در دو گروه تقسیم¬بندی نمود. اكثر صفات از وراثت¬پذیری بالایی برخوردار بودند و اختلاف پایینی بین ضریب تغییرات فنوتیپی و ضریب تغییرات ژنوتیپی وجود داشت كه این‌نتیجه حاكی‌ازآن است‌كه تغییرات بیشتر تحت تأثیر ساختار ژنتیكی بودند تا محیط.

Introduction Legumes are important sources of good quality protein in diet of people and they are valuable as animals feeding. The seed of chickpea plant (Cicer arietinum L.) contains essential protein sources, which plays a significant role in the human diet. Among legumes the resistance of chickpea to dehydration conditions causes a higher productivity. Chickpea has a moderate tolerance to drought conditions, but dehydration reduces its yield significantly. This Characteristics of dehydration tolerance are especially important in plant breeding. The purpose of this study was to evaluate different characteristics affecting the yield of Chickpea and identify the traits that are the most effective methods on yield. Recognizing these traits in breeding programs is useful to select traits can affect the yield. Materials & Methods Understanding the concept of the yield and yield components performance in chickpea breeding programs will be very essential. Cluster analysis, factor analysis, and estimate of heritability were achieved to evaluate the yield performances of chickpea in the present study. A randomized completed block design with four replications was set to investigate thirteen chickpea germplasm at the Research Station of the Agricultural Research Center and Natural Resource at the Khoramabad, ChingaiSarab during 2013-14. These genotypes were included eleven cultivars and two available cultivars (Azad and Local check). Statistical procedures were applied to analyses of data for quantitative traits. Broad sense heritability (h2) was calculated, following Burton. The expected Genetic Advance (GA), with 1% selection intensity (K), was also calculated using the following formula: Gs = K .Ãp . h2 Where Gs is Genetic Advance, Ãp is phenotypic standard deviation of mean performance of population, K (2.06) is the constant standardized selection-differential at 5% and h2 is broad sense heritability. h2 B = Vg/Vp Where Vg genetic variance = (variance between-accessions - variance within-accessions)/n, Vp phenotypic variance = [(variance between-accessions – variance within-accessions)/n] + variance within-accessions, n = number of replications. Genetic advance (GA) = K × (Vp) 0.5 × h2 B Where K = selection intensity at 5% (2.06), Vp = phenotypic variance, h2 B = heritability (broad sense). Phenotypic coefficient of variability (PCV) = Phenotypic variance (Vp) /Mean value of the trait× 100 Genotypic coefficient of variability (GCV) = Genotypic variance (Vg) / Mean value of the trait× 100 Results & Discussion The study of morphological traits among genotypes significant difference was observed in the 1 or 5 percent, which indicates a high genetic variation among studied genotypes. Analysis of variance indicated that the height of plant that measured from the first pod and the number of hollow pods had the highest variance. Nineteen agronomic traits have been classified into four groups which expressed 78/72% diversity of the total variation according to the principle components analysis Each of the first, second, third and fourth components were able to allocate 39.6%, 18.1%, 13.21% and 8.33% respectively. On the other hand cluster analysis using Euclidean distance capable of ranking these genotypes into two groups based on plant characteristics and showing that local cultivars possess similar genetic materials as advanced cultivars. The majority of the traits had high heritability and observed low differentiation between phenotypic coefficient variables and genotypic coefficient variables which demonstrated that the plant diversity was due to genetic make-up rather than environmental factor. Genotype × environment interactions are important sources of variation in crops and the term stability is sometimes used to characterize a genotype, shows a relatively constant yield, independent of changing environmental conditions. The quantitative traits genotypes X98TH75K1-83, LOCALCHECK, AZAD, FLIP98-55C, SAR79J15K3-86, SAR79J710K2-85, SAR79J610K1-86 and SAR79J38K8-85 the cluster analysis were the first group in terms of high yield, according being to the high levels of yield and indigenous masses LOCALCHECK in the group can be concluded that most of these genotypes show adaptation with the environment that has been dry conditions. Conclusion Identification of the yield relationship and traits is an appropriate guide for reformers in the future breeding programs in selecting the best traits. According to the genetic diversity of Present germplasm, they can be used to improve varieties and can also be used to develop genotypes hybridization of these varieties. In the future, it can be found through screening plants that have the greatest resistance as a heritability parents or hybridization of production lines resistant to drought or dry use. It is should be mentioned that the old chickpea landraces and adaptability to environmental conditions with good genes are the genes that can be used in breeding programs.