One of the objectives of wheat improvement at ICARDA is to evaluate the genetic diversity for desirable agronomic traits, especially biotic and abiotic stresses in the cultivated and wild Triticum species; and transfer those gene(s) into good agronomic background. The transfer of alien genes for the improvement of cultivated wheat has been carried out by many scientists (Riley and Kimber 1966; Sharma and Gill 1083; Islam and Shepherd 1988; Tahir 1983, 1985, 1986 and 1990).

Studies at ICARDA on the use of lahdraces and wild Triticum species were initiated in 1980. A very large number of germplasm was evaluated for a number of agronomic characteristics. The studies revealed that there is tremendous genetic variability among the landraces as well as wild Triticum species for the investigated traits (Tahir, 1983; Tahir and Damania, 1990; Damania et al. 1992). The selected germpalsm possessing the desirable gene(s) was employed in crossing program to develop genetic stocks for different traits to expand the base of available genetic diversity against factors depressing the productivity of wheat (Table 3).

The results on the use of three species - Triticum turgidum L. var. dicoccoides (AABB), T. zhukovskyi Men. and Er., and T. kotschyi (Bioss) Bowden are briefly discussed here. These species were used to transfer agronomic traits such as high protein, yellow rust resistance and cold/frost tolerance in durum wheat.


durum x dicoccoides derivatives

The agronomic data of selected yellow rust resistant lines from the durum x dicoccoides crosses showed an improvement over the check varieties for agronomic traits such as grain color and frost tolerance, as well as yellow rust resistance. Although none of the derived lines gave significantly higher yield than the improved check variety Sham 1, a number of them have the potential to do so. None of these lines gave significantly lower yield than the check cultivars. More than 50% of these lines had higher protein content, ranging from 13 to 20 per cent, compared to a protein content of 15.7 and 15.6 per cent, respectively, for Sham 1 and Haurani.

Significant differences in thousand-kernel-weight (TKW) were found. The TKW in the selected lines ranged from 29 to 54 g, compared to 42 and 48 g, respectively, for the two check varieties Sham 1 and Haurani. Eight lines showed significantly lower TKW compared to Sham 1, but all the lines had significantly higher protein content than the checks. Nine lines had significantly higher TKW than improved check variety Sham 1, whereas only one entry (Rubio Candeal/SY 20021/Ente//Stk = ICI 81-22-18) had significantly higher TKW (54 g) than the Haurani check and was equal in protein content compared to the check varieties. Two entries (BD 272/SY20101 and BD 1658/SY20089) had significantly higher TKW and protein content than the check varieties. At least five entries had equal or better TKW as compared to improved check variety Sham 1 and at the same time possessed significantly higher protein content than this check.

The TKW ranged from 33 to 44 g, against 41 g for the checks. There was a high degree of variation within and among derivatives of different cross combinations. No significant differences in days to maturity were observed. However, plant height of the derivatives ranged from 90 to 140 cm, compared to 90 cm and 130 cm for Sham 1 and Haurani, respectively. Statistically significant differences within and among different crosses were observed.

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