Aslani Leila, Gholami Mahdiyeh, Mobli Mostafa, Sabzalian Mohammad Reza
Department of Horticulture, College of Agriculture, Isfahan University of Technology, 84156-83111 Isfahan, Iran.
Department of Agronomy and Plant Breeding, College of Agriculture, Isfahan University of Technology, 84156-83111 Isfahan, Iran.
Physiol Mol Biol Plants. 2020 Nov;26(11):2109-2123. doi: 10.1007/s12298-020-00891-2. Epub 2020 Oct 27.
This experiment aimed to investigate the status of tomato plants in terms of sink or source-limitation of 2 cultivars of greenhouse tomato ( L), 'Grandella' and 'Isabella' under the greenhouse conditions of Iran and to improve the yield and plant growth by manipulating the sink-source balance. To this end, 4 treatments were applied: leaves were not pruned and fruits were pruned to one per truss (1F/3L), leaves were not pruned and fruits were pruned to two per truss (2F/3L), leaves were not pruned and fruits were pruned to three per truss (3F/3L) and no leaf and fruit pruning (control). The results showed that truss pruning reduced the sink demand and consequently, increased the amount of available assimilate for the growth of the remaining fruits or vegetative parts. The negative correlation between the leaf area index and the net assimilation rate and no significant difference in the net assimilation rate between different sink/source ratios showed that the excess leaf area index does not contribute in increasing the assimilate production and hence, total yield. Total fruit weight, harvest index, and the ratio of the ripe fruits to the total fruit led to the highest yield for control plants. No changes in chlorophyll, protein content and nitrate reductase activity were the evidence for the fact that sink/source ratio do not affect light-harvesting and light-utilizing components of photosynthesis. Since the individual weight of fruits increased with decreasing fruit number per trusses, the growth of individual fruits in both cultivars was source-limited and truss pruning can decrease this limitation. Future studies should be carried out to determine the best level of sink/source ratio that in addition to producing an acceptable amount of yield, meets the needs of consumers in the current stressful world by increasing the antioxidant and nutriceutical content of fruits.
本实验旨在研究伊朗温室条件下两个温室番茄品种（L）‘格兰德拉’和‘伊莎贝拉’的库源限制状况，并通过调控库源平衡来提高产量和植株生长。为此，设置了4种处理：不修剪叶片，每穗留1个果实（1F/3L）；不修剪叶片，每穗留2个果实（2F/3L）；不修剪叶片，每穗留3个果实（3F/3L）；不进行叶片和果实修剪（对照）。结果表明，穗修剪降低了库需求，从而增加了可供剩余果实或营养器官生长的同化物量。叶面积指数与净同化率之间呈负相关，不同库源比之间的净同化率无显著差异，这表明过量的叶面积指数无助于增加同化物产量，进而无助于增加总产量。对照植株的总果重、收获指数以及成熟果实与总果实的比例导致了最高产量。叶绿素、蛋白质含量和硝酸还原酶活性没有变化，这证明库源比不影响光合作用的光捕获和光利用成分。由于单果重随着每穗果实数量的减少而增加，两个品种中单个果实的生长均受源限制，穗修剪可以减少这种限制。未来的研究应确定最佳的库源比水平，该水平除了能产生可接受的产量外，还能通过增加果实的抗氧化剂和营养成分含量来满足当前压力环境下消费者的需求。
