| Genetic analysis of tetraploid wheat triticum durum
Desf. Cv Bijaga Yellow by utilization of monopentaploid hybrids*
R.R. HANCHINAL and J.V. GOUD Unrversity of Agricultural Science, Dharwad Campus, Karnataka 580 005, India Tetraploid wheat does not tolerate the loss of a chromosome, or part of a chromosome with the same facility as hexaploid wheat (LONGWELL & SEARS 1963, MOCHIZUKI 1968). Consequently nullisomics, monosomics, telosomics and other tetraploid wheat aneuploids have been little used in genetic analysis of T. durum. In recent years, JOPPA & WILLIAMS (1977a, b) and JOPPA et al.(1979) tried to establish D-genome substitution monosomics and addition and substitution lines in tetraploid wheat. But in the absence of complete series of aneuploids in tetraploid wheat, the other alternative methods are essential for genetic analysis. ALLAN & VOGEL (1960) tried, without success, to analyse smooth awn determination by crossing monosomics of Chinese Spring with a durum wheat which carried this character. More recently KUSPIRA & MILLIS (1967), BOZZINI & GIORGI (1971) and MOKHTARZADEH (1975), using this technique, attempted to identify the chromosomes controlling different quantitative characters in durum wheat. Potentialities and limitations of monopentaploid analysis for assigning genes on different chromosomes for some of the morphological characters in durum wheat cv. Bijaga Yellow are presented in this paper. Material and Methods The first fourteen monosomic lines of hexaploid wheat variety Pb C 591 (monosomic for A or B genome) were crossed as female parents with T. durum cv. Bijaga Yellow. For each line, majority of the F1 populations obtained were of two types i.e. normal eupentaploids with 2n=35 chromosomes and monopentaploids with 2n=34 chromosomes. Few plants in some lines had 2n=33 chromosomes. The plants were raised in earthern pots of uniforn size, providing the uniform environment in green house, at Botany garden, Agril. College, Dharwad. Cytological analysis was performed at the time of flowering. Observations were taken for six characters namely plant height (cm), days to heading, peduncle length (cm), first internode length (cm), second internode length (cm) and number of tillers per plant. The material was grown in completely randomised design with three replications and the analysis of the experiment was performed (SUNDARARAJ et al. 1972). Means and standard errors were calculated in each line. To detect the critical lines means of the monopentaploid populations were compared with eupentaploid mean by students 't' test given by SUNDARARAJ et al. (1972). |
| * Part of the Ph. D. thesis submitted by the first author to the University of Agricultural Sciences, Bangalore, 1980. |
| --> Next |