To achieve nondestructive evaluation of the quality of vegetable soybeans, we have applied chlorophyll fluorescence imaging, which has been used as a non-invasive technology to investigate the ripening and senescence of horticultural products. This study measured changes in chlorophyll content, color (ho), and chlorophyll fluorescence of vegetable soybean pods and seeds and rarely used a nondestructive approach to explore interior quality L-ascorbic acid content. The relationship between chlorophyll fluorescence parameters and visual quality attribute ho, and that between chlorophyll fluorescence parameters and L-ascorbic acid content were performed using partial least square regression (PLSR). Thus, the fluorescence parameters Fm, Fv, Fq_Lss, QY_Lss, and qL_Lss, which make larger contributions to evaluating ho in both whole vegetable soybeans and seeds were selected from 98 chlorophyll fluorescence parameters. Moreover, parameters Fv, Fq_Lss, QY_Lss, qP_Lss, and qL_Lss in seeds, which are important for estimating L-ascorbic acid of seeds were also determined. Most importantly, parameters Fv_Lss and Ft_Lss in whole vegetable soybeans, which may be possible to predict L-ascorbic acid content of seeds by a nondestructive detection. The chlorophyll fluorescence technique presents great potential in examining freshness and estimating the decay in vegetable soybeans.
In this study, we investigated the differences between the Japanese cultivar‘CF Momotaro York’and the Dutch cultivar‘Endeavour’regarding their morphological characteristics and fruit yield under the low-node order pinching and high-density planting system. Fresh fruit yield was not significantly different between both cultivars. While the Japanese cultivar had lower total dry weight, had higher distribution rate to fruit. The Dutch cultivar had a lower extinction coefficient and higher integrated solar radiation at fruit truss. It also had a higher fruit temperature and respiration rate than the Japanese cultivar. These results indicated that the lack of difference in yield between both cultivars and lower distribution ratio to fruit in the Dutch cultivar might be due to higher consumption of photoassimilate, which led to higher respiration rate and fruit temperature caused by higher extinction coefficient.
A real-time photosynthesis and transpiration monitoring system was developed and applied to monitor the time course of photosynthesis and transpiration of fully-grown tomato plant in a semi-commercial greenhouse. The system is composed of an open-bottom chamber and a sensing unit. The chamber encloses a two-meter high tomato plant with transparent film. The two fans equipped at the top of the chamber exhaust interior air and the open bottom allows exterior air to move into the chamber. The inflow- and outflow-air were continuously sampled, and their CO2 and H2O concentrations were measured. The developed system successfully traced the time courses of net photosynthetic and transpiration rates on typical sunny and rainy days. A decrease in net photosynthetic rate, which might be due to the stomatal closure caused by drought stress, was observed on the sunny day. On the other hand, negative net photosynthetic rate and transient increase in net photosynthetic rate and transpiration rate caused by the supplemental lighting were observed on the rainy day. In addition, the dark respiration rate was recognized during nighttime. These results suggest that the developed system can be a useful tool to evaluate the dynamic changes in photosynthesis and transpiration of crops in greenhouse.
Nephrolepis cordifolia (L.) C. Presl is an ornamental plant found in New Zealand and other countries as an invasive species. Allelopathy is a phenomenon that has been proposed as the mechanism for the success of many plant species colonization. However, there are very few studies reported on the allelopathic activity of N. cordifolia. Therefore, we evaluated the allelopathic activity of the aerial and underground parts of N. cordifolia against the growth of test plants. The extracts from the aerial and underground parts of N. cordifolia inhibited the growth of cress, lettuce, barnyard grass, and Italian ryegrass, where the inhibition was proportional to the extract concentration and depended on test plant species. Comparing the average percentage growth and the I50 values revealed the aerial part extracts had a greater inhibitory effect than the underground part extracts. Thus, the aerial part extracts were chromatographed on a silica gel column. Inhibitory activity was found and more pronounced with the fractions eluted with 70 and 80％ ethyl acetate in n-hexane, which inhibited the growth of cress to less than 50％ of control growth. These findings indicate that the aerial part extracts of N. cordifolia may contain inhibitory substances that are responsible for the allelopathic activity.
To develop a male sterile eggplant (Solanum melongena L.), cytoplasm substitution lines of eggplant were produced by continuous backcrossing between S. kurzii Brace ＆ Prain and eggplant using S. kurzii as cytoplasm donor and eggplant as nucleus one by way of the amphidiploid. Analyses of chloroplast DNA and mitochondrial DNA confirmed that all the backcross progenies (the BC1, BC2, BC3, BC4, and BC5) had the cytoplasm from S. kurzii. Anthers in all the backcross progenies were indehiscent type (i.e., pollen non-release type) without segregation. The pollen germination ability of the BC3, BC4 and BC5 plants were about less than 4％. The number of seeds per fruit increased dramatically in the BC4 plants and the average numbers of the BC4 and BC5 plants were about 230 and 360, respectively. The functional male sterility of the anther indehiscent type was shown to be attributed due to incompatibility between the cytoplasm of S. kurzii and nuclear genes of S. melongena. The present CMS plants is promising compared to the one that was backcrossed without going through the amphidiploid, because the CMS is fixed early and the pollen germination ability is extremely low.
Ambient temperature at anthesis is important for pollen germination and pollen tube elongation. In this experiment, the effect of ambient temperature (15, 20, 25, and 30℃) at flowering (1600 to 1900 hours) on subsequent pollen germination was analyzed in‘Chanee’and‘Monthong’durian. The effect of ambient temperature (15, 20, 25, and 30℃) after pollination on pollen tube elongation was also examined in‘Chanee’at 12, 24 and 48 hours after pollination. Low temperatures during anther dehiscence decreased pollen germination in both cultivars; however, the rate was higher in‘Chanee’(27―63％) than‘Monthong’(4―37％) under all temperature conditions. Pollen tube length was significantly shorter in‘Chanee’at 15℃ 12 hours after pollination (12％ the length of the pistil); however, elongation did not differ from that under other temperature conditions at 20℃ (57―63％). These findings suggest the effectiveness of‘Chanee’pollen under low temperatures from flowering through fertilization.