No abstract

A threat of genetic erosion of maize stimulate search for new sources to extend its polymorphism. Teosinte (Zea mays ssp. mexicana), being wild relative of maize, is easily intercrossed with maize and is characterized with a large potential of variability with respect to economically viable attributes, among them being prolific that is having more than one ear. Results are given of long-term selection of maize lines for the attribute of being prolific among the progeny of a hybrid between teosinte (int-350969) and maize. Selection was conducted against the background of soil preparation ideal for maize in a number of attributes that are congruent with prolificacy and synchronous blooming of all or at least majority of ears on a stalk. A wide diversity in the prolificacy of maize was obtained, with the prolificacy coefficient of up to kpr = 3.3 with a complicated mode of inheritance in hybrid progeny. Results of topcrossing with a single-ear sterile tester showed a specific reaction of the lines, provisionally dividing them into 4 groups by the nature of manifestation of the prolificacy in the hybrid progeny. It has been established that the prolific lines, which in hybridization with the single-ear tester are capable of forming more than one ear in the hybrid plant are of higher selective value. At that, it is important to take into account simultaneity of blooming of all the ears at a male plant. Observation of this principle leads to preservation of structure and evenness of ears in upper and lower layer, thus providing their productivity independent of layer on the stalk. Valuable prolific lines have been established for creation of prolific maize hybrids.

The decline in the genetic polymorphism in maize is a cause of concern for many breeders. VIR maize collection represents the world’s maize variety over the past 100 years. The results of the study of maize quantitative properties based on 169 samples from the VIR collection created with the teosinte are shown. KB 595 hybrid, which belongs to the late-season group and is prone to multi-cob was used as a standard. Sowing and evaluation of phenotypic traits were carried out for 2 years in the foothills of Kabardino-Balkaria, in conditions of sufficient soil moisture, in the optimal time. All measurements were carried out on 10 plants with average values of 2 years and an LSD0.05. The results of the research allocated a core collection of 21 samples that promising for hybrid maize breeding and are characterized by significant height and leafiness of the stem, as well as a tendency to form 2 or more cobs on one stem. It has been suggested that the involvement of the selected core collection of 21 samples in thybrid maize breeding programs will significantly expand its genetic polymorphism and increase grain yield in hybrid combinations.