Effects of Selection and Selfing on Agronomical Characteristics of Progeny Lines from Behbahan Landrace Onion

To study the effects of selection and selfing, on progeny lines of Behbahan landrace onion, a five year (1999-2004) experiment was conducted five year at farms of Behbahan region and Behbahan Agriculture Research Station. In the first year, 500 bulbs of two morphotypes (white and red) of Behbahan landrace onion were selected and stored in non controlled storage. In the seconed year, 100 bulbs of each morphotype were selected and planetd. The umbles of each buld were isolated by cloth bags at flowering time. In the third year, self pollinated seeds from each bulb were planted and 57 progeny lines were selected. Bulbs of selected progeny lines were planted for then second selfing in the fourth year. In the fifth year, seeds of the second self pollinated bulbs were planted and 28 progeny lines were selected. The results showed that the growth rate of progeny lines decreased as compared with the source line, due to inbreeding depression, and consequently seedlings emergence percent, seedlings survival percent, leaf hight, mean bulb weight, mean bulb diameter and bulb storability were also decreased. In the other hand duration of seedlings growth of progeny lines in nursery increased compared to the source line. However, the bolting and doubling bulb percent of progeny lines were considerably lower than source line. Bulb off color was not observed in the progeny lines after the second selfeing.