Showing 3 results for Haploid
S. R. Vessal, A. Bagheri, A. Safarnejad,
Volume 6, Issue 2 (7-2002)
Abstract
In order to investigate the androgenic response of chickpea cultivars, two Iranian Chickpea cultivars, Pirooz and Karaj 12-60-31, were used in this study. After 7 to 10 days of cold pretreatment of flower buds, anther containing uninucleate stage of microspores were placed aseptically on MS medium supplemented with various combinations of growth regulators of 2,4-D (1,2 and 3 mg/l) and kinetin (0.1, 0.2 and 0.5 mg/l). Callus regeneration achieved using MS and modified Blayd’s media with various hormones and different sucrose concentrations.
The results indicated that the callus initiation was significantly affected by 2,4-D and kinetin concentrations, and that increasing these hormones reduced callus induction. The best response obtained on media with the lowest concentration levels of 2,4-D and kinetin (1 and 0.2 mg/l, respectively). A highly significant genotypic effect and a genotype 2,4-D interaction were detected, which proved that Pirooz response was the best. Callus differentiation and organogensis occurred in MS medium supplmented with NAA, BA and 3% sucrose. Mature embryos also obtained in modified Blayd’s plus 0.5 mg/l kinetin and 10% sucrose. Cytological studies revealed the presence of haploid cells with chromosome variation in the anther derived callus. Therefore, optimizing the hormone levels of different basal media with a particular sucrose cocentration may improve haploid regeneration in chickpea. It seems a further study should be carried out to characterize calli from induction to regeneration and to determine the effect of cold pretreatment, the results of which could be used to improve anther culture response of chickpea.
B. Heidar, G.h. Saeidi, B.e. Sayed-Tabatabaei,
Volume 11, Issue 42 (1-2008)
Abstract
In this study, factor analysis was conducted to determine the factors which contributed to the variation of quantitative traits and path analysis was performed to find the direct and indirect effects of yield components on grain yield in bread wheat. A doubled haploid population of 157 lines of wheat (Triticum aestivum L.) was evaluated for agronomic and morphological traits, using a randomized complete block design with three replications in 2003 and 2004. The results of factor analysis based on maximum likelihood indicated five factors explaining 80.4% and 73.9% of total variation in 2003 and 2004, respectively. The first factor in 2003 had 30.5% contribution to the total variation, strongly influenced by the traits of pollination date, heading date, flag leaf length and days to maturity. This factor also indicated the negative relationship among the yield components and the importance of relationship between grain yield and some morphological traits. The first factor in 2004 was more affected by grain weight/spike, grains/spike and 1000-grain weight, thus it was named as grain yield factor. The second and third factors in 2003 were considered as plant height and grain yield and in 2004 as maturity and plant height, respectively. The results of path analysis showed that grains/spike had the most direct and positive effects on grain yield in 2003 (1.33) and 2004 (0.87). Because of the negative and high indirect effects of grains/spike via fertile spikes/m2 and 1000-grains weight on grain yield, the correlation coefficient between grain yield and grains/spike was very low. There was not much difference between the phenotypic and genetic direct effects of spike/m2 on grain yield, indicating that their relationship was less affected by environmental conditions. In general, the results showed that grains/spike and spikes/m2 can be more efficient compared to 1000- grains weight for increasing grain yield and can be used as selection indices in breeding programs. Also, according to the results of factor analysis, selection based on the fourth factor including biological yield, spike/m2 and grain yield as selection index can be effective to improve grain yield in breeding programs.
M. Rahimmalek, B.e. Sayed Tabatabaei, S.a. Mohammadi,
Volume 12, Issue 43 (4-2008)
Abstract
Genetic maps with high genome coverage are becoming increasingly useful in both basic and applied genetic researches. In the last decades, the advent of DNA markers has brought about a magnificent revolution in the production of genetic map, especially in wheat. In the present study, AFLP markers were used to saturate linkage map of 107 doubled haploid individuals produced through Fukuho _Komugi × Oligo – Culm crosses received from Japan International Research Center of Agricultural Science (JIRCAS). The framework of genetic map was used as base map for next analysis. AFLP analysis was performed with MseI / PstI as digestive enzymes. The average percentage of polymorphism with AFLP markers was around 16.6%. Data analysis was performed by computer program known as Mapmaker / EXP, Ver. 3.3. In this program, the maximum distance criterion was 50 cM and the minimum LOD equated 3. The drawing of chromosome schema for the linkage groups was performed by Draw map, Ver 1.1. In this analysis, 115 AFLP markers were divided into 10 groups in addition, some of the markers remained unlinked. The supplementary data analysis along with specific SSR markers identified the chromosome loci of the markers. Ultimately, 71.1% of the markers were assigned to genome A, 16.5% to genome B and only 3% to genome D. The AFLP markers filled 11 gaps in 7 chromosomes (2A, 3A, 7A, 2B, 3B, 5B and 7B). The low coverage of genome D was due to the limited polymorphism and its conservation in different populations. Among the chromosomes, maximum number of markers (60) was assigned to the chromosome 7A. The distribution of the markers on this chromosome was not uniform. Such a distribution was related to the grouping AFLP markers within heterochromatin region, particularly around the centromere.
