الفهرس 
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Abstract
Wheat is the most important staple food in Egypt, but unfortunately, Egypt is one of the largest importers of wheat. Gametoclonal variation is heritable genetic variation observed among and within regenerated plants from in vitro culture of haploid gametes. Therefore, assessing gametoclonal variation in plants of 35 gametoclones and their 6 donor Egyptian wheat cultivars was the main goal of this study.
Thirty-five gametoclones (R1& R2) obtained from in vitro anther culture of 6 Egyptian cultivars of spring bread wheats (Triticum aestivum L.) were evaluated at Minia Univ., Egypt during 2008-2010 on agronomical, cytological, and biochemical levels. A field experiment was done in a RCB design with 3 replicates. Eleven agronomical traits were measured, and data were statically analyzed. The genotypes mean was compared using Duncan’s multiple range testing (LSD; P<0.05). Meiotic parameters of gametoclones and their parents were checked using the spikes. Chiasma frequencies and different chromosomal abnormalities were calculated, and data were statically analyzed. Banding pattern of three enzymes (esterase, phosphorylase and α-Amylase) were tested. For isozyme analysis, crushed leaves were used. Cluster analysis was performed with MVSP software.
Agronomical studies: There were significant differences between and within the parental cultivars and its derived gametoclones for most studied characters. Some gametoclones exhibited high performance in yield and/or yield component characters in comparison with its parental cultivars. Cytological studies: All examined genotypes (cultivars and gametoclones) were diploid (2n = 6X = 42 chromosomes) and possess 21 meiotic bivalent units. Most of them were ring-shaped and few were rod-shaped. Significant differences of chiasma frequency between parental cultivars and their derived gametoclones were observed. chromosome lagging, fragment, bridges, outside chromosomes, micronuclei and microcytes were commonly observed. Biochemical studies: Three enzymatic proteins (Esterase, Phosphorylase and α-Amylase) were showed as genetic variation in gametoclones and parental cultivars due to point gene mutation. Cluster analysis of enzymatic patterns, clearly showed that each wheat cultivar and its derived gametoclones are nearly together in the same group with a few exceptions.
The gametoclonal variation induced by anther culture offered an opportunity to broaden the genetic variation of wheats and a wide range of plant characters could be altered and detected by agronomically, cytologically and biochemically analyses. New superior and promising genotypes have been detected. However, genetic stability of those gametoclones are of out most importance when used in plant breeding programs.