ICARDA Caravan 6


	ommon bunt (below left) and Septoria triticae (below, second left), important biotic stresses in Wana. Common bunt is an important seed-borne disease in farmers' fields; septoria strikes mainly in higher-rainfall areas of WANA. Below, second right: Loose smut, another important seed-borne disease. Below right: Yellow rust, a devastating foliar disease, especially in West Asia, and one of the worst enemies of wheat everywhere. The spring bread wheat program puts emphasis on developing germplasm resistant to these stresses. Anther culture, a biotechnological tool used by certain NARS and by CIMMYT/ICARDA in the spring bread-wheat program to develop Hessian-fly and drought-tolerant bread wheat germplasm. The anthers are the male organs of the plant; wheat is self-pollinating. Crosses are made in the field, using parents with different desirable characteristics; anthers are then taken from the first-generation. These anthers are cultured in media in order to develop lines which combine desirable characteristics. An example of this; three double-haploid bread-wheat lines developed using the anther culture technique. This material is seen, above, at the J'maat Shaim station of the Moroccan national research organization,


	INRA, under a natural infestation of hessian fly. This is a devastating insect pest in North Africa causing 100% yield losses, especially in the dry areas of those countries. The material was from CIMMYT/ICARDA and is also tested in Syria. The three varieties are showing good resistance. Morocco, which makes its own double haploids, is now the lead country for development of Hessian-fly resistance, among other things, and has had considerable success.


	Research at ICARDA on photoperiod (effect of duration of light on the maturity and development and phenology of the wheat plant). The CIMMYT/ICARDA program and its partners work as far north as Turkey and as far south as Sudan; there is an enormous difference in latitude and the duration of light during the crop season. Moreover, as it is developing heat- and cold-tolerant varieties, the program studies vernalization (the effect of temperature in the development of the plant).


	Wheat lines with different vernalization-sensitivity at Tel Hadya in summer . The green plants have excessive temperature-sensitivity and will never flower, while the yellow--early--lines are insensitive to vernalization and will flower. Both the national programs and CIMMYT-ICARDA use these techniques of exposing germplasm to different photoperiods and temperatures to identify germplasm with insensitivity to these factors.