Plant Physiology Division, Council of Scientific and Industrial Research - National Botanical Research Institute, Rana Pratap Marg, Lucknow 226 001, India.
Plant Physiol Biochem. 2012 Mar;52:66-76. doi: 10.1016/j.plaphy.2011.11.008. Epub 2011 Nov 28.
Jatropha curcas (L.) trees under north Indian conditions (Lucknow) produce fruits in two major flushes, once during autumn-winter (October-December). The leaves at this time are at the senescence stages and already shedding. The second flush of fruit setting occurs during the summer (April-June) after the leaves have formed during spring (March-April). Photosynthetic performance of detached jatropha fruits was studied at three developmental stages, immature, mature and ripe fruits. Studies were made in both winter and summer fruits in response to light, temperature and vapour pressure deficit (VPD) under controlled conditions to assess the influence of these environmental factors on the photosynthetic performance of jatropha fruits. Immature fruits showed high light saturating point of around 2000 μmol m(-2) s(-1). High VPD did not show an adverse effect on the fruit A. Stomatal conductance (g(s)) showed an inverse behaviour to increasing VPD, however, transpiration (E) was not restricted by the increasing VPD in both seasons. During winter in absence of leaves on the jatropha tree the fruits along with the bark contributes maximum towards photoassimilation. Dark respiration rates (R(d)) monitored in fruit coat and seeds independently, showed maximum R(d) in seeds of mature fruit and these were about five times more than its fruit coat, reflecting the higher energy requirement of the developing fruit during maximum oil synthesis stage. Photosynthesis and fluorescence parameters studied indicate that young jatropha fruits are photosynthetically as efficient as its leaves and play a paramount role in scavenging the high concentration of CO(2) generated by the fruit during respiration.
印度北部条件下（勒克瑙）的麻疯树（Jatropha curcas（L.））在两个主要的果期产果，一次是在秋季至冬季（10 月至 12 月）。此时的叶子处于衰老阶段，已经开始脱落。第二次果期出现在夏季（4 月至 6 月），此时叶子已经在春季（3 月至 4 月）形成。在控制条件下，研究了三个发育阶段（未成熟、成熟和成熟）的离体麻疯果实的光合性能。冬季和夏季果实都对光、温度和蒸气压亏缺（VPD）进行了研究，以评估这些环境因素对麻疯果实光合性能的影响。未成熟果实的光饱和点约为 2000 μmol m(-2) s(-1)，较高。高 VPD 对果实 A 没有不利影响。气孔导度（g(s)）随 VPD 的增加呈反向变化，然而，在两个季节中，蒸腾（E）都不受 VPD 增加的限制。在麻疯树没有叶子的冬季，果实连同树皮对光合作用的贡献最大。在果实皮和种子中分别监测到的暗呼吸速率（R(d)）显示，成熟果实的种子具有最大的 R(d)，是其果实皮的五倍，反映出在最大油脂合成阶段，发育中的果实对能量的需求更高。研究的光合作用和荧光参数表明，年轻的麻疯果实的光合作用效率与其叶子一样高，在清除果实呼吸过程中产生的高浓度 CO(2)方面起着至关重要的作用。
