The results of studies comparing forms of mutant origin spring rape stem height, number of pods on the main inflorescence, pod length and number of seeds in a pod. The height of the stem does not directly belong to the structural elements of the crop. However, in modern breeding this indicator gives importance. The height of the stem is connected with rape resistance and lodging. The problem of short stem is present in both: theoretical and practical terms, and is studied in many countries. Creating dwarf varieties with short stem facilitate harvesting spring rape and leads to reducing economic costs.

Reducing the height of the plants stems mutant origin compared with controls of the original seed varieties Magnat and grade standard Maria observed in all variants. Highlight height stems stunted form – ISP 11-1/7, ISP 11-2/9, ISP 10-3/2, ISP 10-1/4, ISP 11-1/5, which are of practical interest for breeding, as a starting material for dwarf varieties.

Reducing the stem height forms of a mutant origin, compared to grade standard Maria held within 8,6-26,3 cm, and in relation to the initial variety Magnat – 8,0-25,7 cm, depending on the sample.

The greatest reduction in stem height within two years of the study was observed in the number of mutant origin ISP 11-1/7 (82,0 ± 2,1 and 91,3 ± 2,2 cm), which on average amounted to 86.7 cm, 26.3 cm below the grade standard Maria and 25.7 cm - to the initial variety Magnat. The coefficient of variation of this form (V = 7,3 and 8.5%) also indicates a weak variation on this basis during the years under review.

Significant reduction of the height of the stem, as seen in mutant forms of ISP 11-2/9, ISP 10-3/2, ISP 10-1/4, ISP 11-1/5, the average of the two years which ranged from 91.6 to 94.0 cm, compared with grade standard – 113.0 cm and the initial variety – 112.4 cm.

As the number of pods on the main inflorescence numbers found ISP 10-1/4 (37.0 pc)., ISP 11-2/9 (36.6 pc)., ISP 10-1/2 (35.6 pc.) ISP 11-2/8 (35.5 pc)., ISP 11-3/1 (34.8 pc.), which is significantly higher than the initial variety Magnat (25.9 pc.). Our results showed that all sample mutant origin by the number of pods on the main inflorescence exceeded the initial variety Magnat (25.9 pc.) and grade standard Maria (30,4 pcs.), except for form ISP 10-3/2 (29.5 pc.).

Length pods are not a direct part of the structure of seed productivity. Plants with long pods may have larger seeds, but the number of seeds in the pod can be reduced, so the length of the pod does not play a decisive importance in breeding for increased seed yield. However, there are several studies that indicate that an increase in pod length increases and the number of seeds in it. Stability signs pod length, within two years of research found in the form of mutant origin ISP 10-1/2.

In the experiment, we determined only the basic elements of the structure of the harvest that by a great variety models are widely used in breeding programs for enhanced seed performance.

In particular, the number of seeds in the pod is the main breeding grounds of rape, which has a high degree of inheritance.

The seeds degree formation, in the number of seeds in pods, to some extent determined by the genotype and much depends on the type of weather and growing conditions.

The biggest formation seed number was recorded in ISP 10-4/2, the average of the two years of studies was 29.0 seeds units. Mutant form of ISP 10-4/2 exceed grade standard Maria 5.5 seeds in the initial variety Magnat – 6.9 pc.

Key words: spring rape, the form of mutant origin, induced mutagenesis, selection.