Schweitzer L E, Harper J E
Department of Agronomy, Purdue University, West Lafayette, Indiana 47907.
Plant Physiol. 1985 May;78(1):61-5. doi: 10.1104/pp.78.1.61.
The objectives of this study were to determine the effect of pod and seed development on leaf chlorophyll concentration, and on activities of leaf ribulose bisphosphate carboxylase, leaf nitrate reductase, and root nodule acetylene reduction in field-grown soybean (Glycine max [L.] Merr.). Two genetic male-sterile lines and their fertile counterparts (Williams and Clark 63) were compared in both 1978 and 1979. Two additional lines (Wells x Beeson and Wells x Corsoy) were compared in 1979.The expression of male-sterile character was nearly complete as very little outcrossing due to insect pollinators was observed. Male-sterile plants showed a delayed late season decline in leaf chlorophyll content and ribulose bisphosphate carboxylase activity when compared with fertile plants. A slight delay in the loss of in vivo leaf nitrate reductase activity was also observed for male-sterile plants. Root nodule fresh weight and acetylene reduction activity declined slightly more rapidly for fertile lines than for male-sterile lines in both years with differences significant on the last two to three sampling dates as leaf loss occurred in the control plants.Seed development was found to increase slightly, the rate of decline of metabolic activity in fertile lines compared with that of male-sterile lines. However, pod development was not an a priori requirement for leaf and root nodule senescence. Male-sterile plants also lost photosynthetic and nitrogen metabolic competence, but at a slower rate. These results support the concept that pod and seed development does not signal monocarpic senescence per se but rather affects the rate at which senescence occurs after flowering.
本研究的目的是确定荚果和种子发育对田间种植的大豆（Glycine max [L.] Merr.）叶片叶绿素浓度、叶片核酮糖二磷酸羧化酶活性、叶片硝酸还原酶活性以及根瘤乙炔还原活性的影响。在1978年和1979年对两个遗传雄性不育系及其可育对照（Williams和Clark 63）进行了比较。1979年还对另外两个品系（Wells x Beeson和Wells x Corsoy）进行了比较。由于观察到因昆虫传粉导致的异交极少，雄性不育性状的表达几乎完全。与可育植株相比，雄性不育植株在生长季后期叶片叶绿素含量和核酮糖二磷酸羧化酶活性的下降出现延迟。对于雄性不育植株，还观察到体内叶片硝酸还原酶活性丧失略有延迟。在这两年中，可育品系根瘤鲜重和乙炔还原活性的下降比雄性不育品系略快，在最后两到三个采样日期差异显著，因为对照植株出现了叶片脱落。与雄性不育品系相比，发现种子发育使可育品系代谢活性的下降速率略有增加。然而，荚果发育并非叶片和根瘤衰老的先验必要条件。雄性不育植株也丧失了光合和氮代谢能力，但速率较慢。这些结果支持了这样的观点，即荚果和种子发育本身并非单性结实衰老的信号，而是影响开花后衰老发生的速率。
