Characteristic of potato microtuber for seeds

在世界范围内，特别是在难以生产合格种薯的发展中国家，使用带病毒的种子导致马铃薯严重减产。本研究的目的是评估在田间栽培中使用试管薯作为种子的产量潜力。用微型薯（MT）和常规薯块（CT）种子培育了4个不同成熟度的商品品种，历时两年。土壤，水处理（灌溉和未灌溉）下进行避雨棚约30天后发芽（DAS）。MT植物表现出较小的根干重（DW）和叶面积比CT植物，直到约40 DAS。一年内严重干旱对MT植株生长的抑制作用大于CT植株。在最大生长期（约80 ~ 90DAS），两种植物的根干重和叶面积相似。从新梢最大生长期到收获期，MT植株块茎干重的增加与CT植株相同或大于CT植株。在此期间，土壤干燥对干物质生产的影响在MT和CT植物之间没有差异。MT植株的块茎相对干产量为CT植株的70 ~ 90%。早熟品种的相对干物质产量往往小于晚熟品种。目前的研究结果表明，MT种子的使用具有优势的国家，生产认证的种薯是困难的，虽然灌溉在生长初期必须在干燥的土壤条件。

A usage of infected seeds to virus results in severe yield reduction of potato in the world, especially in developing countries, where a production of certified seed tubers is difficult. The purpose of the present study is to evaluate the yield potential in the field cultivation using microtuber, which is produced in-vitro, for seeds. Four commercial varieties of different maturity classes were cultivated using seeds of microtuber (MT) and conventional sized tubers (CT) for two years. Soil, water treatment (irrigated and unirrigated) was conducted under rain shelters since about 30 days after sprouting (DAS). MT plants showed smaller root dry weight (DW) and leaf area than CT plants until about 40 DAS. The supression of growth due to severe drought in one year was greater in MT plants than in CT plants. At the maximum stage of shoot growth (about 80〜90 DAS), however, both plants had similar root DW, and leaf area. During the period from maximum shoot growth stage to harvesting stage, the tuber DW increase in MT plants was the same as or greater than that in CT plants. The effect of soil dryness on dry matter production during this period was not different between MT and CT plants. The relative tuber dry yield of MT plants to CT plants was 70〜90 %. Early varieties tended to make smaller the relative dry yield than late varieties. The present results indicated that a usage of MT seeds has an advantage for the countries where the production of certified seed tubers is difficult, although irrigation during the early growing season must be needed in dry soil condition.