Friday, July 22, 2011

Hybrid Seed Trend

The trend of F1 hybrid seed usage in vegetable is increasing globally in term of species, cultivars and volume of seed used. F1 hybrid vegetable seed can be categorized into hand-pollinated and gene-control pollinated species. The gene-controlled species can be due to the effect of selfincompatibility genes or male sterility genes. The vegetables with both F1 hybrid and openpollinated cultivars were summarized to show their trend of adoption in the world and their F1 seed production method. The development of the hand-pollinated F1 vegetable seed production industry in the world was summarized and the contract production system described. A case study using tomato hybrid seed production in Taiwan was exemplified in details to illustrate the production steps from selection of site to actual growing of the male and female parents, emasculation of the male flowers and pollination, seed extraction and drying, and constraints facing the industry.

Vegetables consist of many species and cultivars, and can be classified in many ways such as by botanical family and species, cultivar group, the edible part, climatic region, user ethnic origin, life cycle and nutrition. In seed production they can be categorized into open-pollinated, F1 hybrid and clonally propagated cultivars. The trend of F1 hybrid seed usage in vegetable crops is increasing globally in term of species, cultivars and volume of seed used. Most of the seed of our main vegetables including tomato, sweet pepper, eggplant, cucumber, squash, pumpkin, melon, watermelon, brassicas such as cabbage, cauliflower, broccoli, Chinese cabbage and radish, and onion in developed countries are of F1 hybrid cultivars. The popularity of F1 hybrid cultivars is due to their vigor, uniformity, disease resistance, stress tolerance and good horticultural traits including earliness and long shelf-life expressed and therefore giving consistent stable high yield. From the breeder point of view, it is a fast and convenient way to combine desirable characters of a vegetable together, for example fruit size and color, plant type and disease resistance, and as a mean to control intellectual property rights through control and protection of the parental lines by the breeders. The latter was the main reason Japanese seed companies applied to protect their cultivars in the 1940s and 1950s.

In F1 hybrid vegetable seed production, vegetables can be divided into two groups: the handpollinated and the gene-control pollinated species. The genetic control system can be due to the selfincompatible system where pollen of the same plant or flower cannot pollinate itself or to the malesterile genetic system where a female plant has no male organ, deformed organ or no functional pollen to pollinate itself. When no such genetic control system is found or when it is not introduced into inbred parental lines, tedious hand-emasculation and pollination have to be used to produce F1 seed. In both the gene-control system and hand-pollinated species sufficient field or female flower isolation have to be maintained to obtain high seed genetic purity.

The hybrid seed in future will dominate for use by most farmers throughtout the world. Established seed company targetted to release new seed to suit the world demand with high productivity, resistance to pests and diseases, durability, market acceptance and consistant supply. Malaysia imports most hybrid seeds from China, Taiwan, Japan, Thailand and other producing country. Total seed industry in Malaysia about RM 35 million annually especially for food crop. There are many improvement for seed industry in Malaysia in future.

M Anem
Muar, Johor,

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