Using spring type of wheat for shortening time to ear emergence of winter wheat by breeding

The study was conducted to examine whether there are real opportunities for the creation of ultra early-winter wheat, using wheat with spring type of development. To achieve the target 24 hybrid combinations between 6 and 8 early spring winter wheat varieties in two consecutive years are made. With different vernalization requirement of plant populations in an artificial climate in the greenhouse winter and spring type plants habit are separate through consistent double selections. Subsequently all the developed lines are checked in respect of field winter cold tolerance for two winter seasons. Combination of spring and winter wheat provides a real opportunity to obtain ultra early forms with winter wheat type of development. About 16% of the plants from crosses of spring parents have similar time to ear emergence (TEE) as the respective spring parent. Time to ear emergence of the spring form does not directly affect the probability of obtaining the desired early plants. The later time to ear emergence of the winter parent, the smaller is the share of the earliest genotypes in the hybrid combinations. The selection of a very early date of time to ear emergence using spring wheat is completely possible and unexpectedly easy to implement. However, preparation of early breeding lines is not sufficient, because they have different grain yield. To have a high productivity must for native climate is to have a high cold resistance. It achieves much more difficult against the earlier date of ear heading date. The results show that it is implicitly associated with the winter cold tolerance of winter parents in every cross combination.