Photosynthesis is the basis of primary productivity on the planet. Crop breeding has sustained steady improvements in yield to keep pace with population growth increases. Yet these advances have not resulted from improving the photosynthetic process per se but rather of altering the way carbon is partitioned within the plant. Mounting evidence suggests that the rate at which crop yields can be boosted by traditional plant breeding approaches is wavering, and they may reach a “yield ceiling” in the foreseeable future. Further increases in yield will likely depend on the targeted manipulation of plant metabolism. Improving photosynthesis poses one such route, with simulations indicating it could have a significant transformative influence on enhancing crop productivity. Here, we summarize recent advances of alternative approaches for the manipulation and enhancement of photosynthesis and their possible application for crop improvement.

No abstract

The muskmelon plants allow several ways to manipulate sources/ drains ratio. The objective of this work was to evaluate characteristics of the productivity and quality of Cantaloupe melon fruits due to the temporary use of row cover and the number of fruits per plant. The experiment was carried out from August to December 2014, at Universidade Federal de Campina Grande (UFCG), Paraiba State, Brazil. The experimental design was randomized blocks with treatments allocated in split plots 5x3, with four replicates. The authors reported permanence time of the row cover at different times in the plot [20, 24, 28, 32, and 36 days after transplanting (DAT)] and, in the subplots, the number of fruits per plant (plants with one fruit, plants with two fruits and fruit-free setting plants). The authors evaluated traits of production and quality of fruits. The permanence time of row cover and number of fruits per plant promoted changes in the productivity and quality of the muskmelon fruits. The permanence of the row cover from 20 to 36 DAT provided reduction in the total soluble solids. The average fruit mass and fruit yield reached the maximum value with the permanence of the row cover up to 26.6 and 25.1 DAT, respectively. Plants with one and two fruits presented higher average fruit mass, but with lower productivity compared to the plant with fruit-free setting.

Squashes and pumpkins are known and grown worldwide, including the Tetsukabuto type, a hybrid of Japanese origin. On this work, we evaluated yield and quality of parthenocarpic fruits of hybrid Tetsukabuto developed with the use of 2,4-D doses, in the climatic conditions of the Brazilian semiarid, in the city of Pombal, state of Paraíba, Brazil. The experiment was carried out from February to May 2013, in complete blocks at random and five replications. Treatments corresponded to five 2,4-D doses (0, 90, 180, 270, and 360 mg/L) applied to female flowers, and a control treatment, where fruits developed out of insect pollinated flowers. We evaluated number of flowers per plant, duration of flowering, number of fruits per plant (used to estimate number of fruits per hectare), fruit set index, fruit mass and transversal and longitudinal diameters, pulp thickness and content of soluble solids, total fruit production and yield. Number of fruits per plant and fruit mass increased 269.5 and 15.4%, respectively, with 212.1 mg/L and 360.0 mg/L of 2,4-D, when compared to the control treatment. Increasing the 2,4-D dose from 0.0 to 241.4 mg/L resulted in 38.2% rise in plant production. Correlations were significant only for number of flowers x number of fruits per plant (NF) and NF x yield, with coefficients of 87.5 and 82.7%, respectively. These results indicate that fruit induction using 2,4-D resulted in higher fruit set, independent of the 2,4-D dose applied.

No abstract