Showing 2 results for Flax.
G. Saeidi, A. Khandan,
Volume 10, Issue 3 (10-2006)
Abstract
The precision of evaluation for agronomic traits is very important in the field experiments to determine the genetic potential of genotypes or effect of treatments. The precision of the experiment mainly depends on the number of replications. The objective of this study was to investigate the effect of number of replications on the precision of genotype evaluation, estimation of variance components and on the heritability for agronomic traits in flax (Linum usitatissimum L.). In this study, nine genotypes of flax were evaluated for different traits, using a randomized complete block design with 8 replications. The results showed that the reduction of error variance due to increasing the number of replications mainly depended upon the type of the trait. For evaluation and estimation of heritability for number of seedlings /m2 and plant height, 3 and 2 replications were suitable, respectively. The results also showed that using more than 2 replications had no considerable effect on the prescision of evaluation, nor on the increase of heritability for days to maturity. Based upon the results, for evaluation of the number of capsules per plant, 3 or 4, and for seeds per capsules, 4 replications can be suggested. For seed yield that is the most important economic trait in flax, a relatively constant estimated mean and broad-sense heritability were obtained with 4 to 8 replicationshowever, using 2 or 3 replications over-estimated the mean of the triat (approximately 11%) and under-estimated the broad-sense heritability about 27% and 10%, respectively. With 2 replications, the estimated mean and broad-sense heritability for seed yield were 2017.6 kg/ha and 72.1%, respectively. Gain from selection for seed yield based on evaluation of genotypes with 2, 3 and 8 replications was estimated as 787, 796 and 798 kg/ha, respectively. Therefore, it seems that 2 replications can also be used for seed yield evaluation of genotypes in breeding programs of flax.
G. Saeidi, M. Khodambashi,
Volume 10, Issue 4 (1-2007)
Abstract
This study was carried out to evaluate the yield potential and other agronomic traits of nine genotypes of flax at two different spring planting dates: April 4 and May 5, 2003 and 2004, using a randomized complete block design with three replications at the Research Farm of Shahrekord University. The results showed that the effects of planting date and genotypes were significant on all of the traits, and the genotypes had a great genetic variation. On average, the range of number of seedlings/m2, maturity, plant height, yield/plant, seed yield and seed oil content of genotypes were 306 to 464, 93.3 to 105.1 days, 28.8 to 58.2cm, 0.274 to 0.569g, 995 to 1423 kg/ha and 32.88 to 34.83%, respectively. The lowest mean of plant height and the highest mean of seed yield/ha were observed for Kordestan local population. Late planting significantly decreased the number of seedlings/m2, days to maturity, plant height, yield/plant and seed yield/ha, while this increased seed oil content. Average of seed yield/plant and seed yield/ha in the first and second planting dates were, respectively 0.506 and 0.414g, and 1598 and 811 kg/ha. Significant interaction of genotype by planting date for seed yield/ha and seed oil content was mostly due to the variation in the reduction of seed yield and increasing or decreasing of seed oil content in some genotypes in the second planting date. The genotypes had a variation of 1358 to 1784 and 632 to 1088 kg/ha for seed yield in the first and second planting dates, respectively. The local population of Kordestan had the highest mean of seed yield in both years. The results of regression analysis and also the correlation coefficients showed that the number of seedlings/m2 and seed yield/plant had the most contribution to the seed yield variation. The trait of number of seeds/capsule and number of capsules/plant were the main and most important yield components affected on seed yield/plant and due to can be used as selection criteria in selection programs to improve seed yield.
