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To study the effects of nitrogen (N), phosphorus (P), and potassium (K) fertilizers on the yield of ‘Jianbao’ pumpkin (Cucurbita maxima Duch), we conducted experiments using the “3414” optimal design scheme in Dehua County, Quanzhou, Fujian, China. Overall, three fertilizer factors (N, P, K) were tested with four fertilization levels (level 0, no fertilizer; level 1, 0.5-times the typical fertilizing amount; level 2, typical fertilizer application; level 3, 1.5-times the typical application), with a total of 14 different fertilization treatments. Based on the results of this study, a corresponding fertilization performance model was established to provide a practical basis for ensuring highly efficient cultivation of pumpkin in the field. Our results showed that the experimental data could not be fitted with a ternary quadratic polynomial fertilizer model, but that it could be fitted with a single-variable quadratic fertilizer model. According to the fitted model, pumpkin yield first increased and then decreased with the increasing amount of N, P, and K used. We identified significant regression relationships between ‘Jianbao’ pumpkin yield and the amount of N, P, and K in the fertilizer. Finally, based on the single-variable quadratic fertilizer model, we suggest that the quantities of N, P, and K fertilizer used for growing 1 ha of ‘Jianbao’ pumpkin should be 390.5, 213.8, and 371.3 kg, respectively.
Luculia pinceana Hook. (Rubiaceae) is a typical distylous species with dimorphic and long-styled monomorphic populations. Within this study, we developed 13 microsatellite markers from L. pinceana using a modified biotin–streptavidin capture method. Polymorphism of each locus was assessed in 30 individuals from four dimorphic populations and one monomorphic population. The average allele number of these microsatellites was 4.153 per locus ranging from three to seven. The observed and expected heterozygosities were from 0.040 to 0.840 and from 0.571 to 0.769, respectively. Additionally, all 13 identified microsatellite markers were successfully amplified in its related species, L. yunnanensis, 10 of which showed polymorphism. These microsatellite markers could provide a useful tool for further study of the breeding system and the population genetic structure in this species and within other Luculia species.
MS is the most commonly used basal medium for the micropropagation of banana (Musa spp.), in which inorganic N source consists of NH4 +-N and NO3 --N, and NH4 +:NO3 - = 1:2. In the present study, basal medium for rooting culture was modified by supplying NO3 --N as the sole N source at the concentration of 17.80 to 19.78 mmol·L-1. Not only was the percentage of qualified plantlets higher than that of MS or ½ MS, but the cost for medium preparation (per liter) was about $0.6 lower than that of MS based on local retail price, for the concentration of N decreased from about 60 mmol·L-1 to nearly 20 mmol·L-1. The effects of four factors: sucrose (25 to 35 g·L-1), NAA (0.2 to 1.0 mg·L-1), IBA (0.2 to 1.0 mg·L-1), and basal medium with modified N source on the percentage of qualified plantlets were studied by using orthogonal design. The variance analysis of data showed that all the four factors significantly affected the process of rooting culture. Among them, sucrose was the most important factor, followed by revised basal medium, IBA, and NAA. The optimal medium for rooting culture was BM II supplemented with 30 g·L-1 sucrose, 0.5 mg·L-1 NAA, and 0.5 mg·L-1 IBA. During the following acclimation phase, >90% of plantlets survived. Chemical name used: 6-benzylaminopurine (BA); indole-3-butyric acid (IBA); α-naphthaleneacetic acid (NAA).
Soils of litchi orchards in China are commonly deficient in nitrogen and potassium. The cultivar Feizixiao litchis planted in a typical acidic upland orchard, which is low in nitrogen and potassium, were used as a subject in field experiments with different ratios of potassium to nitrogen (K2O:N = 0.6, 0.8, 1.0, 1.2, and 1.4). Field experiments were conducted from 2009 to 2012. The effects of K2O:N ratio on the yield, quality, and storability of litchi were investigated and discussed. Results indicated that with the increase of K2O:N ratio, fruit yield initially increased and then decreased, and litchi had the highest yield when K2O:N was 1.2. When K and N fertilizers were applied at the ratio of 1.2, litchi had a better fruit quality with higher vitamin C content, soluble sugar, and soluble solid. With the increase of K2O:N ratio, healthy fruit rate initially increased and then decreased. This rate reached the maximum value when K2O:N was 1.2. Meanwhile, fruit-rotting rate, peel-browning index, cell membrane permeability, and peroxidase (POD) activity decreased at first and then increased and reached the minimum value when the K2O:N ratio was 1.2. Therefore, litchi fruit had the highest yield, better quality, and best storage property when K2O:N was 1.2. Thus, this ratio is recommended for the main litchi production areas in China.
Oriental melon (Cucumis melo var. makuwa Makino) is a fruit with distinctive characteristics that is grown in Fuzhou, China. Fusarium wilt disease management remains a major challenge in the production of this fruit. Here, we performed seven field trials at four locations in Fuzhou, Fujian Province, China, to evaluate the control of fusarium wilt and yield of Oriental melons grafted on two Cucurbita rootstocks [Shengyan Tianzhen (SYTZ) and Nanzhen No. 1 (NZ1)]. During the growing seasons of 2008 to 2011, Oriental melons grafted on SYTZ and NZ1 exhibited dramatically reduced incidences of fusarium wilt disease and increased yields compared with nongrafted Oriental melons. Disease was only recorded in Trial 3 at Hongwei (2009), where plants grafted on SYTZ and NZ1 exhibited 1.05% and 1.1% infection, respectively. In the other six field trials, wilting was not observed at all. In comparison, the incidence of the disease in nongrafted Oriental melons ranged from 45.0% to 100.0%. The use of Cucurbita rootstocks improved the qualitative and quantitative carotenoid profiles, increasing lutein levels (12.7 and 10.8 μg·g−1 of fresh weight, respectively) and ζ-carotene and phytofluene amounts in fruit samples from SYTZ- and NZ1-grafted plants. In particular, the Liyu/NZ1 combination significantly increased β-carotene content ≈4-fold compared with nongrafted samples. In conclusion, Cucurbita rootstocks provided acceptable protection of Oriental melon cv. Liyu against fusarium wilt and improved the productivity and quality of fruits.
Cuttings of sage (Salviaofficinalis `Tricolor'), currant (Ribesaureum), euonymus (Euonymus fortunei var. vegetus), and weigela (Weigela florida `Nana Variegata') were rooted under greenhouse conditions (40% shade) and mist in aerated hydroponic solutions consisting of deionized water, or mixtures of deionized water and nutrients with various levels of electrical conductivity (EC, 0.0625, 0.125, 0.25, and 0.5 dS·m-1) from each of three sources: compost tea from municipal solid waste; wastewater from anaerobic digestion of municipal solid waste; and Hoagland's (control) nutrient solution. Despite differences in species response, rooting tended to be similar with the three nutrient sources. Euonymus rooting percentage increased linearly with increasing EC and was similar with all three nutrient sources (common regression curve, 61% rooting at 0.5 dS·m-1), as did root length (1.4 cm at 0.5 dS·m-1), but root number was unresponsive. Currant rooting percent increased curvilinearly and similarly with nutrient sources (87% calculated maximum rooting at 0.25 dS·m-1), but root number and length were unresponsive. Sage rooting percentage and root number also increased curvilinearly and similarly with nutrient sources (common regression curve, 100% rooting at 0.34 dS·m-1, and 4.1 roots at 0.38 dS·m-1, respectively), as did also root length with the compost tea and Hoagland's (common curve for these two nutrient sources, 11.0 cm at 0.30 dS·m-1), but was unresponsive to wastewater. Weigela was unresponsive to EC or nutrient sources (mean percentage of rooting, 73; root number, 6.5; and root length, 1.9 cm).