Embryo rescue of crosses between diploid and tetraploid grape cultivars and production of triploid plants

Abstract

Five cross combinations Jumeigui×Xinghua No.1, 87-1×Kyoho, Kyoho×Muscat Hamburg, Jumeigui× Hongqitezao and Red globle×Kyoho were used as the testing materials. Factors that affect embryo rescue from crossed seeds between diploid and tetraploid grape were studied applying L₂₅(5⁵) orthogonal experiment design. The effect of inoculation time, medium type and phytohormone concentration was investigated. The chromosome numbers of the progenies were identified by conventional squash method. The results show that inoculation time was the key factor that affects embryo rescue. Other factors’ effects differed according to the combination. The best inoculation time was 55 to 80 days after pollination, which lead to the highest emergence rate of 39.13% to 73.08%. The generation of triploid plants was proved by chromosome number measurement.

Key words: Grape, diploid, tetraploid, embryo rescue, triploid.