Resistance response of drought and heat tolerant spring wheat lines against the cereal cyst nematode, heterodera filipjevi
Wheat (Triticum aestivum L.) is extremely affected by several abiotic and biotic stress factors. Drought and/or heat alongside the parasitism of cereal cyst nematodes of the Heterodera genera can have a combined destructive impact on wheat. Solely, the cereal cyst nematode species Heterodera filipjevi can cause wheat yield losses of up to 50%. Several control measures have been implemented, yet the most economical and convenient control strategy is the use of resistant hosts. Therefore, the main aim of this study was to evaluate the resistant response of 257 spring wheat lines obtained from the International Maize and Wheat Improvement Centre to Heterodera filipjevi that might contain novel sources of resistance and be added as genetic resources for future breeding programs. Also, provide a base for future research to understand the relationship between nematode resistances and drought and heat tolerance. The results indicated that 11 wheat lines (4%) and 36 wheat lines (14%) were resistant and moderately resistant, respectively. High frequency of susceptible and highly susceptible lines and low frequency of resistant lines within this set was also recorded. The linear regression analysis between the number of cysts formed and the resistance response grouping showed a strong, positive, linear correlation. Log-linear regression analysis showed that there is a weak positive correlation between the yield of heat tolerant wheat lines and their resistance to the cyst nematodes as these lines showed tolerance, while there was a weak negative correlation of formed cyst nematodes on the yield of drought tolerant lines. This study was able to add new genetic sources of resistance to Heterodera filipjevi for upcoming breeding programs.