SARATOV, RUSSIA
Saratov State University

The occurence of matroclinal haploids among lines of haploid origin, produced with use of pollen haploinductors

— Tyrnov, VS; Smolkina, YV; Kolesova, AY

A higher frequency (up to 10%) of haploidy can be produced from lines with low (less than 0.1%) matroclinal haploidy if the lines are used as pollen parents. The mechanism of high extent of haploinduction connects with anomalies of sperms, leading to single fertilization. At the present time high effective haploinductors are used for breeding aims. However, the problem of whether the repeated successive production of lines (doubled haploids) can strengthen the tendency to haploidy remains unsolved. On one hand, it is an undesirable phenomenon, as the great number of haploids among hybrids would decrease the harvest. On the other hand, it would give an opportunity for production of the lines — donors of parthenogenesis, necessary for apomictic forms production.

We investigated the lines of 1–5 successive cycles: haploid — line — haploid — line…etc. The haploids were obtained using high effective haploinductors. The derivative lines of these haploids were pollinated by pollen of non-effective haploinductors and other commercial lines for testing the frequency of haploidy. In addition, in these lines the embryo sacs were investigated. Among seeds and seedlings we had observed haploids with frequencies less than 0.1%. Cytoembryological analysis did not discover one case of parthenogenesis even in the 5th cycle. Consequently, use of high haploinducing markers allows us to solve two important problems — producing many haploids by production of homozygous lines and not having haploids by use of these lines and derivative hybrids in the time of commercial production.

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