بررسی ارزیابی ژنتیکی توده های شبدر موجود در بانک ژن گیاهان مرتعی به منظور افزایش عملکرد علوفه و سازگاری

In order to study of genetic variation for forage yield and compatibility among 7 accessions of red clover (Trifolium pratense L.), 7 accessions of white clover (Trifolium repense L.) in pure stand and mix cropping with tall fescue (Festuca aroundinacea L.), an experiment was conducted using randomized complete block design with three replications in rangelands of Mazandaran province, Iran, in two consecutive years (2006-2007). In the first cut in each year five plant were selected at random for recording data. The data were collected for leaflet length, leaflet wide, leaflet area, petiole length, internode length, internodes diameter, florescence number per stolon, peduncle length, tiller per plant, stolen per plant, canopy heigth, persistency, growth type, forage fresh and dry matter yield. Six quality Traits as: crude protein (CP), dry matter digestibility (DMD), water soluble carbohydrates (WSC), crude fiber (CF), neutral detergent fiber (NDF), acid detergent fiber (ADF) and total ash were estimate using NIR methods. Data were analyzed and the means of treatments were comprised using Duncan's test. Simple correlations among traits were estimated and data were subjected to principle components (PCA) and cluster analysis. Results showed that L.E.R for red clovers was less than one, in the other words pure stand of red clovers accessions was much better than mix cropping. In red clover for pure stand accession 1753 with average values of 4547 kg h-1 and for mix cropping accession 2086 with average values of 4017 kg h-1 had highest production. Using principal component analysis, the most important variables were identified. The first three independent components with 60%, 22% and 7% variation accounted for 89% of total variation. The first component petiole length, Internode length and diameter, canopy height, growth type, forage fresh and dry matter yield were important characters for classification. Based :on Ward cluster analysis, entries were divided into 3 groups as clusters 1 ((Mazandaran 4, 1568, 2086, 324 and 618), cluster 2 (1451) and cluster 3 (1753). For white clovers L.E.R was less than one for all of varieties, in other words pure stand had higher production than mix cropping. In pure stand Aran and Tara with average values 2324 and 1909 kg h-I dry matter yield were the best verities, respectively. In mix cropping of white clovers accessions, Tara and Aran with average values of 1336 and 1173 kg h-1had the highest forage yield in the fisrt year, respectively. Using principal component analysis, the first three independent components accounted for 89% of total variation. In the first component leaflet length, leaflet wide, leaflet area, petiole length and peduncle length were important characters for classification with 48% of total variation. Based on ward cluster analysis, varieties were classified into 3 groups as accessions in clusters 1 (Aran, Grasslands and Tara), cluster 2 (Avoca, Chiftan and Tahora) and cluster 3 (Mikanova). Keywords: red clover (Trifolium pratense), white clover (Trifolium repens), Pure stand, mixcropping, Forage yield, morphological traits, PCA, Cluster analysis,

کلیدواژه ها:

تریفولیوم پراتنس ، تریفولیوم رپنس ، شبدر ، ژنوتیپ ها ، تنوع ژنتیکی ، عملکرد زراعی