A large proportion of flowers in the soybean plant [Glycine max (L.) Merr.] abort during development. Water stress imposed during the development of flowers is a major factor increasing the rate of abortion, and long-term or frequent water deficits during this period might decrease yield. The physiological mechanism underlying this phenomenon remains unclear. The objectives of this study were (i) to discover whether a water deficit imposed on a soybean genotype IX93-100 prior to anthesis could cause the abortion of the proximal flowers, which are destined to produce seed-bearing pods at a high rate under optimal conditions, and (ii) to determine whether the abortion was due to the impairment of the pistil (ovule) or stamen (pollen) function. Water stress caused by restriction of watering for 3 d during the preanthesis stage significantly increased the abortion of the proximal flowers. The pistils of well-watered plants, pollinated with either stressed or nonstressed pollen, produced pods at a considerable rate, whereas only a small percentage of water-stressed pistils developed into pods, even when crossed with nonstressed pollen. These results suggest that flower abortion caused by a preanthesis water deficit is not attributed to an impairment of pollen, but was probably due to impairment of ovule function.
ASJC Scopus subject areas
- Agronomy and Crop Science