The Growth Responses of Soybean Plant to Photoperiod and Temperature : II. Responses in chemical constituents

[摘要] Dried materials obtained in the previous study were analyzed for nitrogen, TAC (total sugar and crude starch) (A, B-plot), and other mineral elements (B-plot), to compare the accumulation and distribution of elements with those of dry matter as influenced by photoperiod and temperature: 1) At A-plot, dry matter accumulation and C/N (TAC/Tot-N) ratio of whole plant increased with increase of temperature, while at B-plot they increased with decrease of temperature. At both plots, nitrogen concentrations of plant parts changed in a reverse proportion to their dry weights and Sol-N/Tot-N ratios in lamina increased with decrease of temperature. 2) In general, the concentrations of P, K, Ca plus Mg, Fe, Mn all decreased with decrease of temperature, except that of P in stem which was lowest at 25°-20° and that of K in roots which increased with decrease of temperature. The concentrations of all elements were a little lower under long-day than under short-day. 3) The dry matter production parallelled the elements absorption although the former changed in a wider range than the latter by the temperature treatments. At higher temperatures relatively more Fe and Mn accumulated than dry matter while at lower temperatures almost all elements accumulated relatively less than dry matter. 4) T/R ratio in dry weight decreased with decrease of temperature, while LM/ST ratio in dry weight increased with decrease of it. The accumulation ratios of each element in tops to roots changed in an almost similar way as T/R ratio in dry matter as far as N, P and K are concerned. N and Ca plus Mg accumulated relatively more in the tops as compared with dry matter accumulation, while K, Fe and Mn, especially the latter two, remained much in the roots with a little transport into the tops. P accumulation paralleled dry matter accumulation. 5) LM/ST ratios of K, and Ca plus Mg accumulation were both in parallel with that of dry matter, while those of N, and P were higher than that of dry matter when temperatures were high, indicating a higher rates of accumulation of these elements in lamina at high temperatures.

[学科分类] 农业科学（综合）