SEED-GERMINATION OF RIBES HYBRIDS

Germination of the seed of two Ribes x nidigrolaria Bauer & Bauer cvs. Jostaberry and ORUS-6 varied with pregermination treatment and genotype. Cleaned seed and seed remaining in the berry were prechilled and germinated. Prechilled cleaned seeds gave the most complete and rapid germination. The median response time of seeds in this treatment was 12.3 days. About 42% of cleaned seed of both genotypes germinated after prechilling at 5-degrees-C for 12 weeks. Seeds from the decomposing berry treatments had significantly less germination (16% or lower) with or without a prechilling treatment. This study verifies that prechilling from four to twelve weeks improves germination of cleaned Ribes seed and suggests that sowing decomposing berries is not an efficient technique for laboratory germination.