Four intraspecific hybrids of Nelumbo nucifera, 3 interspecific hybrids from N. nucifera and N. lutea, 69 N. nucifera and 1 N. lutea cultivars were used for the identification of parent-offspring relationships by the ISSR method. Eleven ISSR primers amplified 103 reproducible polymorphic bands. Fifty-eight polymorphic bands were amplified from N. nucifera and could be useful for the identification of cultivars. It suggested that there were significant differences between N. nucifera and N. lutea. With these marks, 16 and 81 polymorphic bands were amplified from artificial hybrid progeny of N. nucifera (Zhongriyouyilian), artificial interspecific hybrid from N. nucifera and N. lutea (Maihiren) and their maternal cultivars, respectively. The relationship among the cultivars followed the genetic principle. However, neither hypothesis of the genetic relationship of ‘Byakkohren’ originating from (Shirokunshishohren × Kourinren) or (America-byakuren × Seigetsuren) was verified. However, 12, 4, 13 and 16 polymorphic bands respectively were amplified from natural hybrids of N. nucifera (Fenwanlian and Meihongchuantai), natural interspecific hybrids from N. nucifera and N. lutea (Meizhonghong and Xiaowufei) and their maternal cultivars. And from the patterns of 69 paternal candidates, only 4 cultivars (Shouxingtao, Rozanpakuren, Shouxingtao and Fenqianye, respectively) fitted genetically and could be reasonably regarded as possible parental plants. These results suggests that ISSR was a useful method for identification of parent-offspring relationship and presumption of pollen parent in lotus.
‘Strawberry Parental Line Nou-2’ was selected from a cross between ‘83118-41’ (‘Frorida693’ × ‘Hinomine’) and ‘Dover’. Its anthracnose resistance is high compared with the anthracnose resistance of ‘Hokowase’ and ‘Dover’. In addition, this line shows a high resistance to Fusarium wilt. No. 2 can be used for anthracnose resistant strawberry breeding, because more than 20% of anthracnose resistant seedlings were observed in the F1 segregated population. No. 2 is available as a breeding material for strawberry cultivars with resistance.
Butterbur is an important vegetable in Japan. In this paper, we present the results of surveying for diploids among cultivated butterbur and production of hybrid plants for harvesting spikes by crossing. It was possible to estimate ploidy level by flow cytometry in butterbur cultivars. ‘Mizubuki’ (Gunma), ‘Yatsugashira’ and ‘Line 4’ were diploid, and ‘Mizubuki’ (Tokushima) and ‘Kibiji’ were triploid. Pollen fertility of male plants of ‘Mizubuki’ (Gunma), ‘Yatsugashira’ and ‘Line 4’ were more than 90% and female plants of ‘Mizubuki’ (Gunma) were fertile. As a results hybrid plants from ‘Mizubuki’ (Gunma) × ‘Yatsugashira’ and ‘Mizubuki’ (Gunma) × ‘Line 4’ were obtained. Average spike yield of hybrid plants from ‘Mizubuki’ (Gunma) × ‘Yatsugashira’ were heavier than that of ‘Mizubuki’ (Gunma). There were several hybrid plants that produced many spikes of these hybrid plants, and developed less anthocyanin pigments at the bracts. Therefore, there is a possibility of selecting a new cultivar for harvesting spikes from hybrid plants of ‘Mizubuki’ (Gunma) × ‘Yatsugashira’.
The present study was conducted to clarify the effects of 4 successive applications of processed liquid cattle manure (PLCM) on the growth and yield of tomatoes in sand and soil cultures using isolated beds (spring 2000, fall 2000, spring 2001 and fall 2001 in experiments 1, 2, 3 and 4, respectively). Treatment solutions consisted of 1) Control (commercial nutrient solutions), 2) PLCM with KH2PO4, and 3) PLCM with macronutrients. In experiments 3 and 4, PLCM diluted with tap water was applied to soil as an additional treatment. Plant growth was less at the PLCM treatments compared to the control, and marketable fruit yield at the PLCM treatments was reduced to about 70%, on average, of the control in all experiments. The EC and Cl and K concentration of PLCM were extremely high. The reduction of plant growth and fruit yields might be caused by salinity stress. Ca concentration in leaves was lower at the PLCM compared to the control. The higher incidence of blossom-end rotted fruit at the PLCM treatments might be induced by the lower uptake of Ca. There was no salt accumulation in sand and soil or successive cropping injury observed during the experiment. It was suggested that PLCM could be useful in drip fertigation in soil culture because of the soil buffering capacity.
The snapdragon (Antirrhinum majus. L.) cv. ‘Maryland Pink’ and ‘Light Pink Butterfly II’ were grown using two methods of raising seedlings and four night temperature settings for pinching cultivation in winter. For both cultivars, the flowering of the second node shoots was earlier, and the yield of cut flowers was increased using the method of raising seedling without temporary planting. A suitable night temperature for cut flower production of ‘Maryland Pink’ was suggested to be a minimum of 11°C starting from the middle of November. The largest yields of cut flowers of ‘Light Pink Butterfly II’ was obtained when the plants were grown under a night temperature over 11°C starting from the middle of November, then increased to 16°C from the middle of December. But the stem length of ‘Light Pink Butterfly II’ were shorter when the plants were grown under a night temperature of 16°C.
The effects of fruit thinning, defoliation, and training methods, using lateral shoots for increasing leaf areas, on fruit soluble solids content and yields of tomatoes were investigvated. Restricted fruit load per fruit truss by fruit thinning did not result in increment of total yields, marketable yields or fruit soluble solids content. Defoliation and training methods for increasing leaf areas did not influence total yields or marketable yields. Fruit soluble solids content was lowered by defoliation and increased with increasing leaf areas by leaving the lateral shoot just below the fruit truss.
A method of regulating the emergence of flower stalks and flowering of Phalaenopsis ‘Ensyu’ × Phal. ‘White Dream’ (Exp. 1 and Exp. 2) and Phal. ‘Miki Saito’ × Phal. ‘Jenco Arctic Mass’ (Exp. 3) was investigated. When the emerged flower stalks were removed at their bases, new flower stalks always emerged and their flowers bloomed after 3.5 months (Exp. 1). If the flower buds were continuously removed when pea-sized, new flower stalks did not emerge for about 10 months (Exp. 2). If the disbudded flower stalks were excised at their bases early in April or early in November, new flower stalks always emerged and their flowers bloomed after 120-130 days (Exp. 3). These results indicated that the timing of flower stalk emergence and flowering in Phalaenopsis could be regulated by a combination of flower bud removal and flower stalk excision.
Yielding and labor saving ability of a short-internode variety of squash (Cucurbita maxima Duch. var. Tsurunashiyakko) was compared with the vining-type variety ‘Ebisu’. The yield of ‘Tsurunashiyakko’ increased as the row width was decreased from 2.0 m to 1.0 m (plant populations from 100 to 200 plants per are), while average fruit weight declined adversely. As a result, a row width of 1.5 m seemed to be appropriate for the optimum production of ‘Tsurunashiyakko’. To save labor in nursing seedlings, 3 methods (25 days in a 12 cm plastic pot, 7 days in a 45 mL cell tray (72 cells per tray) and direct sowing) were compared. ‘Tsurunashiyakko’ has a high stability of fruit set, and a yield of one fruit per plant was ensured in all treatment. For ‘Ebisu’, the number of fruit decreased as the nursing period was shortened. This suggests that it is possible to save labor without reducing yield in ‘Tsurunashiyakko’, however, this is not so in the case of ‘Ebisu’. In comparison with nursing ‘Ebisu’ seedlings in a 12 cm plastic pot, approximately 75% of the labor reduction, as well as a yield of more than 200 kg/a, were ensured when ‘Tsurunashiyakko’ were nursed in a 45 mL cell tray. The results indicate that ‘Tsurunashiyakko’ has a high adaptability to labor-saving cultivation.
Dendranthema indicum var. hortense plants were brushed gently with a soft plastic dusting brush 15 times (back and forth) per day for 7, 14, or 21 days, or brushed 10, 20, or 30 times per day for 15 days. Twenty-six days after treatment ended, plant heights were reduced significantly by all treatments. As time elapsed after brushing treatments, the dwarfing effect was decreased but the effect persisted after 21-day treatment with both suppression of both branch length and leaf area. Branching increased in the plants treated 30 times for 14 days and 15 times for 21 days. Both the fresh weight and dry weight of the shoot and root were also reduced. However, the chlorophyll content was not affected 80 days after planting. Stomatal width was deceased in plants treated 15 times for 21 days, but stomatal length was not affected by brushing. Number of stomata was increased greatly in plants treated 15 times for 21 days compared to the control. Days to emergence of flower buds were shortened by 6 days in plants treated 15 times for 21 days. The number of flowers increased in the plants treated 30 times for 14 days and 15 times for 21 days. Bases on this experiment, it is recommended to brush plants 15 times per day for 3 weeks to promote Dendranthema pot production with high quality.
The effect of ethylene treatment on the germination of tweezers-harvested seeds was examined in two strawberry cultivars, ‘Sachinoka’ and ‘Asuka-ruby’. In both cultivars, seeds treated with 100, 200, 500 and 1,000 ppm ethephon solution exhibited significantly higher germination rates than those of seeds treated with 0 ppm solution. However, almost all seeds treated with ethephon solution exhibited abnormal root growth. In ‘Asuka-ruby’, the germination rates of tweezers-harvested seeds treated with 1,000 ppm ethylene gas for 24 and 48 hours were significantly higher than those of control seeds. From these results, it can be considered that short-term incubation with ethylene gas is effective for increment of the seed germination rate, while the germination of tweezers-harvested strawberry seeds without any treatment remained poor.
The fruits of a Japanese persimmon ‘Fuyu’ were preserved at low (5°C) and normal temperature (20°C) for 30 days, and relations between change in fruit firmness and changes in respiration rate, ethylene production rate, weight reduction rate and antioxidative levels were investigated. During storage at normal temperature, with decreasing the fruit firmness, the activity of antioxidative enzymes, such as superoxide dismutase, catalase and peroxidase, respiration rate, ethylene production rate and weight reduction ratio increased, and the concentration of ascorbic acid decreased. At low-temperature storage, activities of catalase and peroxidase decreased until the 10th day and thereafter increased and that of ascorbate peroxidase gradually increased. The concentration of ascorbic acid did not decrease until the 15th day. These findings suggest that the antioxidative level of the Japanese persimmon ‘Fuyu’ fruits is closely related with softening and that the relationship of active oxygen to the process of softening under low and normal temperature might be different.
Most of tomatoes produced in Japan have been consumed for fresh eat. Accordingly, processing tomato cultivars suitable for cooking are not popular at all in the Japanese markets. The study to evaluate the cooking suitability of processing tomato cultivars had been conducted. Twenty-three determinate type cultivars were grown in open fields in Tohoku National Agricultural Experiment Station. Growth, yield, fruit storability, cooking suitability, taste of heated juice, etc. were analyzed. Based on these analyses, we selected ‘Toyokoma’, ‘Natsunokoma’ and ‘Nitakikoma’ as cultivars suitable for cooking in northern Japan. We obtained the positive relation between juice taste and the sugar/acid ratio, and negative relation between heated juice viscosity and dry matter rate of pulp. These relations could contribute for selection and breeding of new tomato cultivars for cooking.