稻屬種間雜交擴大栽培稻之遺傳變異Ⅰ.引進野生稻種原之特性評估

本文描述本所於民國78年自IRRI引進，分屬9個種的25個野生稻系統之種種農藝性狀，以建立稻屬種間雜交擴大栽培稻遺傳變異之基本資料。在本所環境條件下經兩個期作之觀察評估得知，各引進野稻種均具芒、柱頭外露、二次枝梗稀疏及極易落粒等特性。除O. australiensis為「無葉耳」及「白色柱頭」外，其它稻種均有葉耳且柱頭為紫色。大體而言，不同的種有不同的生長特性及外表形態；而同一種除開花時間、穗軸角度、穗抽出度、穗型、芒色與種皮顏色較一致外，各系統的性狀表現不一。期作對各野生稻種的生育日數、稈長、分蘗數及穗長之影響較顯著，而以稈長及分蘗數之差異最大。在第一期作環境條件下，有13個系統（包括O. barthii、O. australiensis、O. officinalis三稻種及O. punctata半數的系統）不抽穗，其餘抽穗者之生育日數及株高均比二期作顯著增加。野生稻之開花時間介於清晨6點到下午4點之間，隨系統而異，雜交授粉時間應隨所使用野生稻種原之不同而有所調整。野生稻種雖有二倍數與四倍體之分，但僅從外表形態難以分辨出其倍數性。

關鍵字

稻屬；種間雜交；栽培稻；遺傳變異；野生稻

並列摘要

In order to broaden genetic (including cytoplasmic) diversity of Formosan cultivated rice through interspecific hybridization within Genus Oryzeae, 25 wild rice accessions belonging to nine Oryza species were introduced to the Institute from International Rice Research Institute in 1989. The purpose of this report was to present some important information as the wild rice germplasm should be included in the future rice breeding programs. Under the environmental conditions of Taichung area, all of the wild rice accessions come out with awn varied in length, stigma outgrowing, secondary branching light and panicle shattering absolutely high. They were also characterized by a marked auricle on the leaves and purple stigma in the spikelets with an exception of O. australiensis which was auricleless and white stigma. In general, significant differences in growth habits and morphological characteristics were found among the species; and intraspecific differences were also observed for the characteristics except flowering time, panicle axis angle, panicle exsertion, panicle type, awn color, and seed coat color. Variation due to crop season on growth duration, culm length, tiller number, and panicle length were evident, especially for culm length and tiller number. A total of 13 out of the 25 accessions failed to head in the first crop season. The rest, headed in the first crop season, had culm length and tiller number significantly high than those in the second crop season. A wide range of flowering time, from 6 ant to 4 pm varied with entries under Taichung environmental conditions, was observed for the entries. Therefore, reasonable pollination schedule has to be arranged depending on the entries used. Based on the chromosome makeup, the introduced wild rice entries can be classified as diploids and/or tetraploids. However, it is difficult to identify their ploidy based on the morphological features.

並列關鍵字

Genus Qryzeae ； Interspecific hybridization ； Cultivated rice ； Genetic diversity ； Wild rice

國際替代計量

稻屬種間雜交擴大栽培稻之遺傳變異Ⅰ.引進野生稻種原之特性評估

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