水稻秧苗耐寒性之研究　Ⅱ.低溫處理前後溫度對耐寒性之影響

Cold Tolerance of Rice at Seeding Stage. Ⅱ. Effects of Air Temperatures before and after Chilling Treatment on Cold Tolerance

曾東海(T. H. Tseng) ； 鄧耀宗(Y. C. Teng)

《中華農業研究》 34卷2期 (1985/06) Pp. 145-156

https://doi.org/10.29951/JARC.198506.0003

摘要

以新竹矮腳尖、新竹糯4號、臺農秈育2414、IR30、IR29、PI162319、USSR No.45、Pratao等8品種的秧苗達3.5~4葉齡時，以日夜溫10℃處理9天，處理前後分別以30/25℃及20/15℃培育秧苗，共2×2=4處理，採複因子完全逢機設計，重複10次，生長箱之光照強度為270μEm^(-2) Sec^(-1)光照時讓爲每天12小時，探討秧苗生長期之溫度對其耐寒性之影響，結果發現：高溫之前處理雖能促進秧苗之伸長，但其伸長勢與耐寒性無關，低溫處理前後之溫度顯著地影響低溫處理之結果，低溫處理前以30/25℃培育時，較易顯出耐寒性之品種間差異，且各品種之平均存活率較低，葉片滲出液之導電度與秧苗存活率呈顯著的負相關。在低溫處理的第3或6天以後，所測之葉片導電度可反應該品種之耐寒性。鮮葉重受低溫處理影響顯著。且與存活率呈正相關關係。表示低溫處理後測得之葉片滲出液導電度與鮮葉重可供測驗水稻苗期耐寒性指標之一。

並列摘要

Eight rice varieties were used as experimental materials to study the effects of air temperatures (30/25℃ or 20/15℃) before and after low temperature treatment (10/10℃) on the cold tolerance of rice seedlings. The duration for pre- and post-low temperature treatment was 1 and 2 weeks, respectively. Seedlings at 3.5-4 leaf age were subjected to 10℃ of low temperature treatment for 9 days. The light intensity was 270μEm^(-2)s^(-1) for 12 hrs per day in the growth chabmers.
The air temperatures before and after the low temperature treatment did affect the growth rate of rice seedlings in terms of seedling height. In general, seedlings under higher temperature at pre-treatment stage showed higher growth rate and the rate was maintained throughout the low temperature treatment period. Seedlings under lower temperature at pre-treatment stage, however, tended to have higher growth rate at the post treatment stage.
Results also showed that the treatment of 10℃ for 9 days was adequate to reveal the varietal differences in conductivity of cell leakage, especially for pre- 30/25℃ treatment to show a higher and wider range of conductivity. A similar result was also obtained on fresh leaf weight.
Based on the data of survival rate, which were read two weeks after low temperature treatment, rice seedlings under high temperature (30/25℃) at the pre-treatment stage tended to have lower survival rate for semi-cold tolerant and cold sensitive varieties, especially with the low temperature (20/15℃) at post-treatment stage. However, rice seedlings under pre-30/25℃ and post-20/15℃ treatment showed the highest survival rate among the 4 treatments. In addition, the result from variance analysis revealed that the variety×treatment interaction reached the 1% significant level. Cold tolerant varieties such as HOW 4 and USSR No. 45 had little variation under different treatments. The semi-cold-tolerant varieties and cold sensitive varieties, however, had a relatively low survival rate if the air temperature at the pre-treatment satage was high, hut the survival rate was higher if the air temperature at the pre-treatment stage was low.
Regression analysis between conductivity of cell leakge and survival rate, and fresh leaf weight and survival rate indicated that both conductivity of cell leakage and fresh leaf weight, measured at the 9th day of low temperature treatment, can be used as indicators for screening the cold tolerant rice varieties at seedling stage.