Propagation and field evaluation of virus-free and true-to-type planting materials of garlic (Allium sativum L.)
2007
Patena, L.F.
Garlic is one of the most economically important crops in the Philippines. Average yield is low compared to other countries due to low quality planting materials which can be traced to its conventional method of propagation, i.e. by cloves. Traditionally, farmers use previous crop's harvest as planting materials on a continuous basis. This poses a high risk of transmitting diseases from one generation to the next and of losing varieties. To solve the problems mentioned above, the technology of producing virus-free and true-to-type garlic planting materials, was developed and adapted it for mass production of bulbs for distribution to farmers. In increasing bulb production in the field, organic farming was incorporated to add value to the crop. The developed technology consisted of the following: 1) improved tissue culture protocol (with cold pre-treatment and thermo therapy), 2) production of in vitro bulblets (G sub 0 bulblets), 3) enzyme-linked immunosorbent assay or ELISA to index the materials for presence/absence of virus, 4) isozyme (protein) markers to check if the tissue-cultured materials are true-to-type, i.e. without genetic variations from the initial materials, and 5) field planting (using organic farming utilizing fermented fruit juice) of tissue-cultured bulblets to produce more bulbs (G sub 0 G sub 1 G sub 2 G sup n) and to increase bulb size from generation to generation. When in vitro bulblets (G sub 0) were planted in the soil under greenhouse or field conditions, small bulbs, first generation (G sub 1) bulbs, were obtained. These G sub 1 bulbs increased to its normal size when planted in the field to produce the second generation (G sub 2) bulbs. During the next season, bulbs from the previous season were planted to produce the next generation bulbs. Increase of planting materials from G sub 2 to G sub 3 was 6X for Ilocos White, 5X for Mindoro and 7X for Tan Bolter. Disease indexing was done using ELISA. All the varieties cultured both the local cones and the low cost, imported garlic, called 'Elephant garlic', were indexed. Results showed that the 'Elephant garlic' has the highest virus infection as compared to the locally-grown varieties. This means that importation of garlic bulbs should be done with caution so as not to introduce other diseases associated with the virus. The technology provided a system of producing garlic bulbs which are disease-free, true-to-type and with the added value of having been produced organically.
显示更多 [+] 显示较少 [-]