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- Author or Editor: M. Yamaguchi x
Upon visiting one of the many grocery stores in San Francisco's Chinatown, one is amazed by the vast array of strange-looking exotic fruits and vegetables on display, and wonders where they came from. By questioning the proprietor and examining the labels on the crates and cartons, the visitor soon realizes that most of the produce was grown in California, some less than 50 miles from San Francisco.
The concentration of fructose, glucose, sucrose, raffinose, and stachyose in the leaves, stem, and fruit of the muskmelon plant (Cucumis melo L.) was determined using paper and gas chromatography. Stachyose was the predominant sugar in the leaves but was absent in the developing fruit. Most of the 14C label in 14CO2-treated leaves was associated with stachyose, while the 14C label in the fruit was associated with fructose and glucose. The concentration of stachyose was highest in the leaves, intermediate in the stem, and lowest in the fruit.
Tomato seeds were more responsive than wheat or lettuce seeds to the presence of an inhibitor in the juice of tomato fruits. Seed germination and seedling growth decreased with increasing concentrations of juice. Inhibition of seed germination in 20% juice with an osmotic concentration of less than 0.1 M was significantly less than in 0.1 M glucose or mannitol with 0.01 M citric acid at pH 4.4. The inhibitor in tomato juice was thermostable, but the effect decreased with prolonged storage at -20°C. There were cultivar differences in the amount of inhibitor present in ripe tomato fruits.
Pollen fertility and inheritance patterns of male sterility were analyzed in various cultivars and selections of Japanese apricot (Prunus mume Sieb. et Zucc.). Male sterility segregated differently in two types of crosses. In pairings of male-sterile and male-fertile parents, progenies were either all male-fertile, all male-sterile, or mixed. Crossing two male-fertile plants resulted in offspring that were either all male-fertile or mixed. Male sterility in Japanese apricot appears to be of the gene-cytoplasmic type. The genotypes of 10 cultivars and three selections are determined.
Seeds in fruit of bell pepper (Capsicum annuum `California Wonder') plants grown in nutrient solutions deficient in potassium (<3 mmol·L-1) showed a higher incidence of sprouting (i.e., vivipary) than seeds in fruit from plants grown at adequate potassium levels (6 mmol·L-1). Tissue analysis showed a progressive drop in the leaf content of potassium with increasing plant maturation for all levels of potassium nutrition. However, potassium in fruit and seeds increased at later stages of maturity. ABA was extracted, isolated and identified from bell pepper seeds obtained from fruit grown under the potassium treatments (0.0, 0.6, 1.5, 3.0, and 6.0 mmol·L-1) at five fruit maturity stages (mature-green to overripe). At early fruit maturity stages, there were no significant differences in seed ABA content in the fruit from the different potassium treatments. However, differences in ABA content and vivipary among the potassium treatments became highly significant as the fruit matured. The concentration of ABA in seeds of potassium-deficient treatments was ≈14% of the control (0.4 versus 2.8 μg·g-1 dry mass). High concentrations of ABA in bell pepper seeds were associated with low incidence of vivipary and high potassium content in the leaves, fruit and nutrient solution.
Individual leaves of Cucumis melo L. acropetal to a developing fruit were treated with a pulse of 14CO2. The level of 14C in the leaves, internodes, and fruits was determined after various periods of time when the leaf at the 3rd node acropetal to the fruit was treated. Leaves at the same node as the fruit, the 2nd, the 3rd, the 6th, and the 18th node acropetal to the fruit were treated and the level of 14C in the leaf, internodes, and fruit was determined after 2 hours. The percent of the incorporated 14C which was exported from the leaf was strongly affected both by time and leaf position relative to the fruit. Leaves which were 3 nodes acropetal to the fruit exported 65% of the label in 6 hours, while those further from the fruit retained the label longer. The influence of the fruit on the movement of 14C label is limited to a few internode lengths along the branch.
N,N-bis(phosphonomethyl)glycine (glyphosine) was sprayed at 0, 200, 400, 800, 1600 ppm on vine foliage of ‘PMR-45’ muskmelon (Cucumis melo L.) once about 2 weeks after initial flowering. Branch length and number of leaves were reduced at 1600 ppm. Melon weight was increased at 200 ppm about 6.6%, while soluble solids content was increased at all concentrations above the control about 10%. Both effects were most evident toward the end of the season. Triacontanol, applied at 0.01, 1.0, and 10.0 ppm as a foliar spray at the 8 to 10 leaf stage had no effect on muskmelons.
Japanese apricot (Prunus mume) originated in south-eastern China and is one of the major fruit trees in Japan. The major cultivars of Japanese apricot are self-incompatible. Self-incompatibility of Japanese apricot is gametophytic, the same as other Prunus species. Since S-genotype of every cultivar remained unclear until now, we examined molecular markers to determine S-genotype which was explored based on the information about S-RNase of other Prunus spiecies. Total DNA isolated from six cultivars was PCR-amplified by oligonucleotide primers designed from conserved region of Prunus S-RNase Every six cultivars yielded two amplified bands. In total, seven kind of polymorphism in molecular size were determined among those six cultivar, controlled pollination tests were carried out among cultivars that showed same band pattern, and these cross-combinations indicated cross-incompatibility. So, we were made clear that S-genotype of Japanese apricot could effectively and easily be determined by PCR method, and that there exists seven S-gene at least.
Radioactive (2–chloroethyl)phosphonic acid (ethephon) was applied to leaves and fruits of ‘Tiny Tim’ tomato and ‘Pioneer’ cucumber and to seedlings of ‘Yellow Crookneck’ summer squash. During the first day, slightly over 21% of the applied 14C-ethephon was converted to 14C-ethylene by the squash plants, and 10 to 15% was converted by the tomato plants. A week after treatment the rate of 14C-ethylene production decreased rapidly to less than 1% per day. Increases in rates of production of total ethylene following treatment were attributed to the decomposition of ethephon. Radioactive CO2 production was small, amounting to about 0.1% of the 14C applied.
Seven days following treatment of tomato leaves, about 15% of the 14C was translocated to developing fruits and lesser amounts to other parts of the plant. In the squash seedling, from 3 to 9% was translocated after 2 days from the site of application to other tissues. Twenty–five days after application to cucumber leaves, the fruits containted only 0.3% of the applied 14C–ethephon. In the tomato tissue the radioactivity was present as 14C–ethephon, but in the squash seedling tissue much of the radioactivity was present in a new compound.
Three cultivars of onions used for dehydration were grown in a greenhouse at constant soil (bulb) temperatures of 13°, 18°, 24°, and 29°C. Growth of tops was best at 24° and poorest at 13°; the number of foliage leaves increased until about the time the bulbs reached half maximum diameter; thereafter the number declined, due to cessation of new foliage leaves and senescence of old leaves. In all plants at 13°, visible bulbing occurred before emergence of the scape. Bulbs matured earliest at 29° but yields were highest at 18° and 24°. The length of bulbs increased with increasing temperature, but the diameters were not significantly different, resulting in very elongated bulbs at high soil temperatures. Soil temperature had no effect on lateral bud formation (doubles). Pungency or votatile propyl sulfur compounds were highly correlated with temperature but percent dry wt, total sugars, and bulb pinking were not correlated.