Partitioning of Photoassimilates by Four Potato Clones¹

Abstract

The partitioning of photoassimilates was compared for four field‐grown potato clones. Russet Burbank was used as a standard for comparison, and the other three clones were selected because they generally produce higher yields and have higher photosynthetic rates than Russet Burbank. In this study we examined whether the patterns of assimilate partitioning change with the stage of plant development and with the time after labelling and also whether these partitioning patterns vary for different clones. The most recently‐expanded leaf on each plant was labelled with 14CO2 at three different growth stages: the beginning of tuberization, 3 and 5‐weeks later; and representative plants from each treatment were harvested at three time intervals: 2 h after labelling, 7 days after labelling, and the end of the growing season. The total quantity of 14C‐1abel exported from the exposed leaf increased beth with age of the plant and with time after labelling. The exported assimilates were partitioned in varying quantities to all plant organs, including trace amounts to the mother tubers (seed pieces). Some of the assimilates produced after tuber set and originally partitioned to other organs may have been remobilized to the tubers near the end of the season. At later growth stages, some clones delivered assimilates to the tubers more rapidly than others. The potential exists for plant breeders to combine late season maintenance of photosynthesis with rapid and/or greater delivery of assimilates to the tubers as an approach for increasing tuber yield.

Relationship of Photosynthesis and Harvest Index to Sweet Potato Yield

“…The high-yielding genotypes 'Georgia Jet', 'Travis', and selection 75-96-1 had both high 14 C translocation rates and high storage root yields. Similarly, high-yielding peanut genotypes (Bhagsari and Brown, 1976) and potato clones (Gawronska et al, 1984) also had higher 14 C translocation rates than the low-yielding genotypes.…”

Duration of the growth cycle and the yield potential of potato genotypes

“…Besides, from the initial development stages of the plant, the vegetative growth was more accelerated in the late clones. The vigorous growth of the late clones, besides being related to the greater photosynthetic capacity, is also important for an increase in the remobilization of photoassimilates to the tubers towards the end of the growth cycle (Moorby 1970, Gawronska et al 1984. Moreover, the growth cycle was correlated to tuber yield from the harvest at 83 DAP (r = 0.49*) on, and the correlation coefficient gradually increased until the last harvest (r = 0.66**).…”

“…Under these circumstances, strategies to increase the productivity level could focus on an extended maintenance of the photosynthetically active leaf area, which is directly related to a greater duration of the growth cycle. Gawronska et al (1984) mention the potential for genetic improvement to combine a long growth cycle with a quick and/or high allocation of photoassimilates to the tubers, with a consequent increment of the final crop yield.…”

Modelling development and growth of the potato crop influenced by temperature and daylength: LINTUL-POTATO

“…LINTUL-POT ATO is partly based on dry matter accumulation with allocation governed by a dominant tuber sink (Spitters 1990;Kooman 1995;Spitters and Schapendonk 1990) using quantitative relationships from Moorby (1968), Sale (1974) and Gawronska et al (1984). Part of the model was described by Kooman (1995) and the complete set of equations is given here in Table 1 with Table 2 describing the meaning of the acronyms and the (initial or optimum) values of the variables and parameters used.…”