不同生态型粟的光合特性比较研究

 本试验收集到我国12个省（市、自治区）不同生态型粟70余个，光合特性分析结果表明：谷子光合强度平均值为38.88毫克，不同生态型差异较大，变幅为20.00-61.70毫克；光呼吸平均值为2.19毫克，变幅在0.60-5.90毫克；光补偿点变幅在1.2-4.0kLx；谷子的CO#-2补偿点变幅在6.0-22.5ppm，其平均值为13.6ppm。除谷子的光补偿点较高外，其它各项光合特性较接近C#-4型植物。这些结果为遗传育种和栽培管理上充分利用我国丰富的谷子资源提供了重要依据。

COMPARATIVE STUDIES ON THE PHOTOSYNTHESIS CHARACTERS IN FOXTAIL MILLET OF DIFFERENT ECOTYPES

More than seventy foxtail millet materials of different ecotypes were collected from twelve provinces (cities or autonomous regions) in China, and grown in pots. The photosynthesis characters were studied with infrared ray CO_2gas analyzer. Photosynthetic rates (Pn) of sixty-five tested materials varied from 20.00 to 61.70mg CO_2/dm-2.hr, with average of 38.88 mg, Pn of most (78.5%) cultivars were above 31.00 mg. Furthermore, Pn of 64.6% cultivars were between 31.00-50.00 mg, which were near the photosynthesis character of C4-type plants.Photorespiration (PR) of 30 materials tested varied from 0.60 to 5.90mg, average was 2.19mg, which belonged to low PR type.PR values varied considerably for materials collected from different regions.For materials from the South the PR values were relatively low, while for materials from the North the PR values were relatively high, thus the PR value may be associated with latitude.There were exceptions to this rule which may be the results of cultivar introduction and cross breeding.Light compensation points (LCP) of tested materials varied between 1200 to 4000 lux, indicating there were big differences among the materials in the use of dim light.The CO_2 compensaton point (CCP) of the materials varied between 6.0 to 22.5 ppm, with average of 13.61 ppmo. Compared to the photosynthesis characters of typical C3-type plant (wheat) and C4-type plant (maize), foxtail millet has high Pn, low PR, and relatively low CCP, it belongs to C4-type plant. We also noticed that photosynthesis characters of different foxtail millet cultivars varied greatly, which is significant for its breeding and cultivation.