Authors
1
Research Institute of Forests and Rangelands. P.O. Box, 13185-116, Tehran, Iran. Email: aajafari@rifr-ac.org
2
Former postgraduate student of Islamic Azad University, Jiroft Branch
3
Research Institute of Forests and Rangelands. P.O. Box, 13185-116, Tehran, Iran
Abstract
In order to evaluate dry matter yield and morphologic traits of 18 foreign and domestic ecotypes/varieties alfalfa (Medicago sativa), were planted in Alborz Research Center, Karaj, Iran. These ecotypes/varieties were evaluated under optimum and drought stress conditions using complete block design with three replications during 1999-2001. The data were collected and analyzed for forage dry matter yield, flowering date, summer growth score, winter growth score, stem density, plant height, leaf/stem ratio, insect resistance (Hyper postica Gyll), crude protein percent and crude fiber percent for mean of each year and combined over two years.
The results showed significant differences among ecotypes/varieties for, flowering date, summer growth score, crude protein and crude fiber percent in first year and for plant height, leaf/stem ratio and dry matter yield in the second year under optimum condition. In drought stress, the results showed significant differences for plant height (first year) and crude protein and summer growth score (second year). In combined analysis over two years, the effect of year was significant for all traits in both experiments. The genotype ´ year interaction effects were significant only for plant height and crude fiber under optimum condition. For flowering date Yazdi and Cankreep, were the earliest and Maraghah and Harati were the latest varieties under optomum condition. For plant height, Sent Luis1009, USA2564 and Hamadani under optomum and Hamadani, FAO2436 and hunter-river under drought stress had the higher plant height. For leaf/stem ratio Maraghah and US-2564 had the highest values under optomum and drought stress, respectively. For annual dry matter yield, Hamadani and FAO-2435, with an average of 7 ton/he/year and Simerchenskaia, FAO-2435 and Nomad with 1.5 ton/he/year had the higher forage production under optimum and drought stress conditions, respectively. In general, Hamadani, Harati, FAO2433, FAO2436 were suggested for cultivating under optimum condition and Hamadani, Gharah Youngeh, Hunterriver, Sent Luis1529 and Numad were suggested for dryland farming system. However, Gharah Youngeh had better quality than Hamadani.
Phenotypic correlation between traits were consistent over two coditions. Plant height and dry matter yield were negatively correlated with crude protein and positively correlated with fiber content. Plant height was positively correlated with winter growth and negatively with flowering date. Summer growth score was positively correlated with both dry matte yield and winter growth score. Leaf/stem ratio was positively correlated with crude protein and negatively with plant density and plant height.
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