CO_2加富对黄瓜的增产效应及其原因分析

EFFECT OF CO_2 ENRICHMENT ON CUCUMBER YIELD AND THE CAUSE ANALYSIS

黄瓜加富CO_2,营养生长和生殖生长旺盛,产量增加23％～37％。增产原因至少包括:(1)提高了细胞间隙的CO_2浓度,降低了RuBPO/RuBPC活性比,抑制了光呼吸,增加了光合强度;(2)促进细胞的生长,叶片增厚,叶面积扩大;(3)C/N比提高,促进了花芽分化。本文还介绍了天然CO_2施肥方法,CO_2浓度日变化以及RuBisCO羧化与加氧活性同时测定的方法。

CO_2 gas, carried with steel bottles from CO_2 gas well, was applied into tunnel greenhouse through erected plastic pipclines.The CO_2 concentration in the tunnel greenhouse and the rates of photosynthesis and pnotorespiration of the single leaf and population were determined with infrared CO_2 gas analyser, and at the same time, the double activities of RuBPCase and RuBPOase were measured with oxygen electrode and ^(14)C isotope method. After applying CO_2, the rates of vegetative and reproductive growth of cucumber were faster and the yield was 23～37％ higher than that in normal air. The causes of yield increase included, at least, three aspects: 1. Under CO_2 enrichmemt, the intcreellular CO_2 concentration increased, consequently, the ratio of RuBPO/RuBPC decreased and the photosynthetic rates of leaf and population significantly rised (Fig. 2, 3; Table 1, 2). 2. The growth of cells was promoted, resulting in thicker leaves and larger leaf area (Fig. 5). 3. The increase of the ratio of C/N after applying CO_2, promoted differentiation of the floral buds (Table 3). In the test, we also obscrved the chlorophyll content and total nitrogen in leaves growing in CO_2 enrichment conditon decreased. Thus, it was suggested that more N-fertilizer applie to the cucumber, which grew under CO_2 enrichment, would led to more production.