We investigated the effects of N nutrition on growth and carbohydrate partitioning of pepper (Capsicum annuum L., cv. Maor) seedlings in the greenhouse and on their subsequent recovery and development after transplanting. Seedlings received 0, 30, 100, or 200 mg N/liter for 14 days, after which they were transplanted and received 100 mg N/liter. Nitrogen levels below 100 mg·liter−1 inhibited shoot growth and leaf chlorophyll content; both were severely inhibited in the absence of supplemental N. Root growth had a negative relation with N supply; an enhanced root: shoot ratio was observed under low-N regimes. On a unit-leaf-area basis, CO2 fixation was not affected when N was present; however, it was greatly inhibited in the absence of N. Changes in the leaf starch and soluble sugar concentrations occurred as a function of N supply and leaf age. In the roots, low N led to lower sucrose and higher levels of hexose and starch. More sucrose was transported and accumulated into leaf veins of low-N tissue. Exogenously supplied 14C-labeled sucrose was rapidly converted into starch in the low-N tissue. Seedlings that received 100 mg N/liter had the highest post-transplant growth rate and flowered earlier. Carbohydrate status of young pepper seedlings influenced their post-transplant recovery. Optimal N supply is essential for full recovery and development of transplants.
149 POSTER SESSION 6E (Abstr. 371–378) Photosynthesis & Partitioning–Cross-commodity
149 POSTER SESSION 6E (Abstr. 371–378) Photosynthesis & Partitioning–Cross-commodity
adaptation to environmental stress. This study focused on how exogenous application of ABA could affect Ca transport and partitioning between the leaves and fruit of tomato in protected culture environments. Calcium movement through the plant is regulated by
Non flowering Alstroemeria `Regina' plants were divided into aerial components: stems and apical and basal leaves or underground components: rhizome, storage roots, stele and fibrous roots. Samples were collected from distal and proximal ends of the rhizome to allow comparisons between structures of different ages. Ethanol soluble sugars were extracted and measured using HPLC. Starch was degraded to glucose using amyloglucosidase and measured.
There were no age differences in the starch, total soluble sugar (TSUGAR) or total soluble carbohydrates (TCHO) in the rhizome or aerial portions of the plant. There was a preferential partitioning of starch, sucrose, TSUGAR and TCHO to underground plant parts. The storage roots were the primary sink for the stored carbohydrates. Stems contained large concentration of glucose while fructose was found in storage roots and old stems. Sucrose was found primarily in old steles and storage roots. Starch was partitioned almost exclusively into the storage roots with no difference due to age of the storage root. Up to 42% of the TCHO in the old storage roots was composed of a carbohydrate which co-chromatogramed with melezitose using HPLC.
)]. Whole plant sampling can be used to look at nutrient partitioning and distribution/redistribution to provide a full picture of nutrient dynamics. The present study was conducted to investigate the seasonal pattern of macronutrient uptake and
) also reported that the dry weight of spikes of Argentine wheat cultivars was related to partitioning to spikes, although yield was more closely related with the grain/spike ratio rather than the dry weight of spikes. Saitoh et al. (1993) reported that
) ( Burns, 2006 ). Present efforts of breeding, screening programs, or both for improving the NUE of cultivars (e.g., through improved initial root growth rate, maximum root expansion, root/shoot DW, and N partitioning) at either limiting or nonlimiting N
Abstract
Total variation in yield per plant of long English cucumbers is partitioned by regression procedures into increments of variation due to successive morphological components. Variation in these increments is partitioned further by conventional analysis of variance. The results of this 2-way partitioning describe how treatments produce differences in yield through their effects on yield component variation. The method (2dimensional partitioning, TDP) offers a simple way to account for growth and yield variation in crops.
processes, including photosynthesis, respiration, growth, development (phenology and morphology), and partitioning ( White and Reynolds, 2003 ). However, quantifying crop responses to temperature has been difficult because different plant organs typically