溫度對直播水稻分蘖特性與成熟生理之影響

Effect of Temperature on the Tillering Characteristics and Developmental Physiology of directly-sowed Rice

陳建山(Chein-Shan Chen) ； 劉大江(Dah-Jiang Liu)

《中華農業研究》 28卷3期 (1979/09) Pp. 199-206

https://doi.org/10.29951/JARC.197909.0009

摘要

本試驗之目的在探討溫度對直播水稻之開始分蘖節位及成熟期地上部碳水化台物省量之影響，以提供本省二期稻作穗數與結實率減低原因之參考。試驗採用臺中秈2號與臺南5號二水稻品種，從播種至成熱期間在人工控制氣候室之玻璃室內，按最高分蘖期、孕穗期及抽穗期，分別給予如下三種日／夜溫度轉換處理：30/25→25/20→20/15℃,25/20→30／25→30/25℃，與20/15→25/20→30/25℃，結果摘要如下：
1．直播水稻之開始分蘖節位在主稈第2或第3節位。低溫(20/15℃)生長之直播水稻開始分蘖節位，比高溫(30/25℃)或中溫(25/20℃)提高，品種間，稉稻又比秈稻高，唯品種或處理間穗數之差異概不顯著。
2．不同品種或處理之葉綠素濃度皆自最高分蘖期後逐漸下降，而由高溫降至低溫處理之水稻，葉綠素含量自孕穗期起，顯著地比其他處理爲低。
3．在葉或稈和葉鞘的非構造性碳水化合物，由高溫降至低溫之處理，自孕穗期起，含量逐漸上升，但另二個溫度處理，在成熟期變化較少，含量亦較前者低，兩品種的變化趨勢相同。
4．在低溫成熟水稻之千粒重與結實百分率最差，推究原因，可能因低溫影響光合作用器官功能與光合成產物轉流受阻礙的緣故。
有鑑於比，直播密植栽培有能力補償高溫對分蘖的影響，有利於在二期稻作推廣栽培，而爲避免低溫影響二期稻作的結實率，推廣早熟稻亦是值得嘗試的途徑。

並列摘要

The purpose of this study was to elucidate the effects of temperature on the node-position of the first-emerged tiller after planting and on the contents of total non-structural carbohydrates (TNC) in the plant tissues during various growth stage of directly-sowed rice in order to provide references for the causes of low yield of the second crop rice.
Two varieties, Taichung Sen No. 2 (indica type) and Tainan No. 5 (japonica type), were used in this study. Temperature treatments were carried out in the glassrooms of phytotron from sowing to maturity. Three treament.s of various temperature duration, i. e., 30/25-25、20-20/15, 25/20-30/25-30/25, and 20/15-25/20-30/25℃ were designed and changes of temperature within individual treatment were held at maximum tillering, booting and heading stages of the growth course of rice plants.
It was found that the directly-sowed rice cultured under low temperature (20/15℃) had higher node-position of the first-emerged tiller than those grown under warm (25/20℃) or high (30/25℃) temperature. Furthermore, the node-position of the first-emerged tiller was lower for indica than for japonica rice. However, no significant difference in panicle number per hill was found between varieties among temperature treatments.
Chlorophyll concentration was highest at the maximum tillering stage and decreased thereafter in all temperature treatments. The decrease in chlorophyll concentration was more prominent for plants grown from a high to low temperature than those grown from a low to high temperature change.
TNC contents in leaves and culm plus sheaths accumulated evidently from booting stage until harvest when rice plants were grown at a high to low temperature regime. Little changes were observed for other temperature treatments.
The percentage of fully ripened grains and 1,000-grain weight were lower in the treatmnt high to low. The probable cause was the inefficiency of photosynthetic apparatus and the handicap of carbohydrate translocation from culm to panicle as a result of low temperatrue effect.
The method of directly-sowing rice was applicable to the second crop season because decrease in tiller number due to high temperature could be compensated by high-density sowing practice. Early-maturing varieties were also recommended in order to conquer the handicap of carbohydrate translocation during the grain developmental stage.