2020 Vol. 35, No. 3
Display Method:
2020, 35(3): 243-253.
doi: 10.19303/j.issn.1008-0384.2020.03.001
Abstract:
Objective Microsatellite markers were used to analyze the correlation between the genetic polymorphisms and productive traits of Texel×Kazakh sheep for breed improvement. Method Eleven microsatellite marker sites were selected for the study. Genetic polymorphisms of 108 sheep were determined using PCR and capillary electrophoresis. Correlation between the genotypes and productive traits of the sheep at each site was analyzed. Result A total of 91 alleles were detected at 11 microsatellite loci with an averaged number of alleles at 8.273, an observed heterozygosity at 0.428, an expected heterozygosity at 0.815, and a content of polymorphic information at 0.789. The following loci were found extremely significantly or significantly correlate with their corresponding traits: AMEL, ETH152, INRA006 and INRA023 loci with primary weight, weaning weight, pre-mortem weight, and weight of the salamander; CSRD247 locus with lengths of carcass and legs; INRA005, MAF214 and MCM527 with leg will be obliquely long, the legs are obliquely long and the ankle width; INRA172 and OARFCB20 with widths of hip, chest and shoulder; and, INRA063 with chest depth. Conclusion The 11 selected microsatellite markers were rich in genetic polymorphisms among the sheep population. They all correlated in different degrees with the various productive traits of a sheep suggesting a potential tool in breeding of Texel×Kazakh sheep with increased meat producing capacity.
2020, 35(3): 254-259.
doi: 10.19303/j.issn.1008-0384.2020.03.002
Abstract:
Objective A microencapsulated forage was evaluated to replace live worms for feeding at early development stage of the carnivorous Lanzhou catfish (Silurus lanzhouensis Chen) based on the resulting larval weaning, juvenile growth, and enzyme activities in digestive tracts. Method Two experiments were conducted with the microencapsulated forage (MF) introduced to the fish at different ages. In the first experiment, 3 groups of randomly divided catfish larvae were fed with either MF (WW), a combination of MF and live worms (WL) or live preys (LL). Larval survive rate and growth in 30 d were monitored following the feeding. The second experiment examined the effects of WW versus minced meat (RR) for feed on the growth and metabolism of the juveniles for 115 d. Result (1) Domesticating the fish in the WW group was significantly the least effective among all. However, the survival rate of (94.3±0.9)% on the fish fed with WW was significantly higher than the other two forages (P ＜0.05). And the body weight increase of the catfish in the WL group were the fastest (P ＜0.05). Significant differences in SGR and AGR of LL group were observed compared with the other two treatments (P ＜0.05) . (2) MF appeared to significantly promote the growth from larval to juvenile stage of the catfish. There were significant differences on the performances by the different forages (P ＜0.05). Except for no difference between 2 treatments for the enzymatic activities of pepsin in the midgut, hindgut and stomach, the enzymatic activities of lipase, amylase, and pepsin in the pancreas, stomach, foregut, midgut, and hindgut of the fish tended to be higher in the WW group fed on WF than on RR. Conclusion MF significantly improved the growth and maintain a relatively uniform size of catfish at early development stages. The use of MF for catfish aquaculture was highly recommended.
2020, 35(3): 260-265.
doi: 10.19303/j.issn.1008-0384.2020.03.003
Abstract:
Objective Effects of lysine content in diet on the reproductive performance, serum biochemistry, and excretion nitrogen of sows in late gestation stage were determined. Method A total of 64 healthy, pregnant, crossbred sows (Large White×Landrace) with 3–7 parities and a similar parturition date was randomly divided into 4 groups. Each group consisting of 16 replicates and one reference sow were fed with forage containing a digestible lysine level at 0.58%, 0.63%, 0.68% or 0.73%. Feeding the experimental diet on the sows started at the 80th day after artificial insemination and finished after farrowing. Result The weight of newly born litters in the 0.63% lysine group was significantly higher than that in the 0.58% group by 8.26%, and that in the 0.73% group by 7.87% (P＜0.05). The piglets at birth weighed significantly higher in the 0.63% group than the 0.58% group by 5.84% (P＜0.05). In the 0.63% group, the serum urea nitrogen was significantly lower than either the 0.58%, 0.68% or 0.73% group; the insulin significantly higher than the 0.58% or the 0.73% group; the serum lysine and threonine significantly lower than the 0.58% or the 0.73% group; the leucine and isoleucine significantly lower than the 0.73% group; the crude protein digestibility significantly higher than the 0.73% group; and, the excretion nitrogen significantly lower than the 0.68% or the 0.73% group. Conclusion When the sows were fed at late gestation stage with a diet that contained 0.63% digestible lysine, an improved reproductive performance in them could be expected.
2020, 35(3): 266-272.
doi: 10.19303/j.issn.1008-0384.2020.03.004
Abstract:
Objective Effects of Enterococcus faecium 8296 on the growth, nutrient digestibility, and serum biochemistry of weaned piglets were studied. Method Sixty 21-day-old, weaned, Duroc×Landrace×Yorkshire-crossbred piglets were randomly divided into 3 groups with 5 replicates per group and 4 piglets per replicate. The groups were fed with either a basal diet as control, the basal diet with 0.1% addition of E. faecium (EF1) or the basal diet with 0.3% addition of E. faecium (EF2) for 30 d. Growth performance, apparent nutrient digestibility, and serum biochemical indices of the piglets during the testing period were determined for analysis. Result ① The piglets in the EF1 group had a significant increase on the average daily weight gain (ADG) (P＜0.05) and a significant reduction on the feed to gain (F/G) ratio (P＜0.05) over control. The piglets in EF2 increased significantly on ADG (P＜0.01) and on average daily feed intake (ADFI) (P＜0.05), while decreased significantly on F/G (P＜0.01) as compared to control. ② The apparent digestibility on ether extract (EE) and calcium (Ca) of the EF2 piglets was significantly higher than control (P＜0.05), and that on phosphorus (P) extremely significantly higher than control (P＜0.01). ③ The aspartate aminotransferase (AST) activity in serum of the EF1 piglets was significantly lower than that of control (P＜0.01), but the serum immunoglobulin M (IgM) content was significantly higher than that of control (P＜0.05). The EF2 piglets had the serum globulin (GLO) , P and IgG significantly (P＜0.05) and AST activity extremely significantly lower than those of control (P＜0.01). The serum triglycerides (TG) and immunoglobulin M (IgM) of the EF2 piglets were significantly (P＜0.05) and the serum immunoglobulin A (IgA) was extremely significantly higher than those of control (P＜0.01). Conclusion A diet supplemented with 0.3% of E. faecium 8296 appeared to significantly enhance the growth, nutrient digestibility, and immunity of the weaned piglets.
2020, 35(3): 273-279.
doi: 10.19303/j.issn.1008-0384.2020.03.005
Abstract:
Objective Means to utilize straws of tomato and chili pepper plants after harvest on solanaceous vegetable fields were explored. Method Pot experiments were conducted to study the effects of crushed fresh straws, crushed sun-dried straws, and composted straws from tomato and chili pepper plants for fertilization/soil conditioning on the seedling growth of solanaceous vegetables (i.e., tomato, chili, and eggplant) and the allelopathy of the vegetable field. Result Application of the crushed fresh straws not only significantly inhibited the seedling growth but also induced a significant negative allelopathic effect on the soil. The effect was particularly pronounced in 30 d after the straws were turned into the ground where same family of vegetables was planted. Whereas, when the crushed sun-dried straws were applied, a negative allelopathic effect on the 3 solanaceous vegetables also appeared in 10 d but dissipated after 30 d and followed by a significantly vigorous root growth of the seedlings. On the other hand, the composted straws showed a positive allelopathic effect immediately after the application that continued to enhance with time. Conclusion For solanaceous vegetable farming, tomato and chili straws after composting could conceivably be returned to the field for desirable results. The crushed sun-dried waste material could be added to the soil at least 30 d after seedling planting to mitigate the negative effect. Using the fresh straws, however, would require further study to firstly resolve the harms brought about by the direct application.
2020, 35(3): 280-285.
doi: 10.19303/j.issn.1008-0384.2020.03.006
Abstract:
Objective Based on the inverse relation between the fruit cracking rate and fruit shape index (FSI), thresholds to achieve optimal pomelo thinning on Duweiwendan, Citrus grandis (L.) Osbeck. cv. Duweiwendan, was studied for orchard management. Method From 2016 to 2018, 8 660 pomelos on Duweiwendan trees were collected from the major producing areas in Xianyou County, Fujian to determine the fruit crack width (FCW) and FSI at the orchards. Distribution of the data compiled was used to access the cost/benefit to arrive at a recommended threshold for the fruit thinning. Result The upper limit of FSI at 0.90 was found to be the inflection point on the iterative regression simulation of logistic cumulative curve of the operation. According to the curve, at FSI≤0.83 a relatively high efficiency of cracked fruit elimination was obtained. At FSI≤0.80, 20% of the pomelos were discarded resulting in a definition greater than 2.0. At an FSI＞0.80, the amount of thinned fruits increased significantly, while the corresponding gain dropped to below 2.0. Conversely, if the FSI was reduced to less than 0.80, the operational efficiency declined. The peak of the logistic cumulative curve on the 3-year fruit crack rates, as well as the field statistics, indicated that a thinning threshold at FSI≤0.80 was appropriate with little concern of excessive loss on the fruit harvest. Conclusion An optimal threshold of FSI≤0.80 to improve the financial gain with a minimized harvest reduction was recommended for the Duweiwendan pomelo orchards. An FSI up to 0.83 could be considered in years when a bumper pomelo harvest is expected.
2020, 35(3): 286-294.
doi: 10.19303/j.issn.1008-0384.2020.03.007
Abstract:
Objective Ornamental property of various Hydrangea paniculata, the few increasingly popular flowering woody plants that blossom in summer, were studied for the development, utilization and breeding of new varieties. Method Fifteen phenotypic characteristics on the branches, leaves and flowers of 17 varieties of H. paniculata were examined for a systematic analysis and classification. Result The morphological variations among the varieties were generally minute, with a coefficient between 0.88% and 5.66% on florets, between 0.88%~8.58% on branches and leaves, and between 2.08% and 14.83% on inflorescence. The flowering lasted 23 d to 54 d. The correlations between inflorescence transverse diameter (x1) and volume of inflorescence (x5) had a coefficient of 0.929, between inflorescence longitudinal diameter (x2) and x5 0.752, between color of a flower after it changes color (x9) and color of aging branches (y6) 0.777, and between leave length (y1) and leave width (y2) 0.882. Based on the characteristics, the 17 varieties could be clustered into 2 to 5 categories. Conclusion The branch, leaf and flower phenotypes of the 17 varieties of H. paniculata differed to varying degrees, with the inflorescence being the greatest. The correlations among the characteristics were significant between x1 and x5, between x2 and x5, between x9 and y6, and between y1 and y2. The information would be of value in genetic studies on H. paniculata, as well as, in selecting, developing and utilizing superior new varieties.
2020, 35(3): 295-302.
doi: 10.19303/j.issn.1008-0384.2020.03.008
Abstract:
Objective Viability of stored Chrysanthemum× morifolium pollens were determined for germplasm preservation. Method Pollen viability of 10 chrysanthemum cultivars were determined by an in vitro germination method for medium selection. Viability of pollens stored in the selected medium at 4℃, −20℃ or −80℃ for 60 d and 120 d was monitored every 15 d. After a 120 d storage, hybridization pollination with the pollens was performed for fructification evaluation. Result The medium for optimum pollen germination was ME3 with the additions of 200 g·L−1 PEG 4 000 and 6 g·L−1 agar. All pollens stored in the chosen medium germinated with a significantly superior rate. The pollen viability decreased after 60d storage. Among the 10 chrysanthemum, Variety ‘5’, ‘52’, ‘64’, and ‘85’ had slower declining rates on the pollen viability but higher viability after the 120 d storage at −80℃ with full fructification upon pollination than the others. Of the 4 varieties, Variety ‘5’ had the highest pollen fructifying rate of 8 seeds per inflorescence on average. Conclusion The medium for pollen germination and genotype of cultivar as well as the temperature and duration of storage could all affect the viability of the chrysanthemum pollens. On the optimally formulated medium at −80℃ for 120 d, the pollens from Variety ‘5’ maintained a high viability with full fructification at pollination for satisfactory chrysanthemum cross breeding.
2020, 35(3): 303-308.
doi: 10.19303/j.issn.1008-0384.2020.03.009
Abstract:
Objective Optimal medium formulation and effect of plant growth regulators for germination of Prunus salicina var. cordata cv. Younai embryos were investigated. Method Culture media with or without addition of plant growth regulators were varied to determine the effects on the embryonic germination of Younai seeds. Result The highest germination rate of the semi-abortive breeding embryos inoculated in the WPM medium without any added growth regulator was 40.00%. With the regulator addition, the WPM medium including 2.0 mg·L−1 6-BA and 0.1 mg·L−1 IBA (Treatment No. 6) achieved a maximum germination rate of 46.67%. For the intact embryos, the rate reached 100.00% on either MS, WPM, or WPM with the addition of either 1.0 mg·L−1 6-BA and 0.1 mg·L−1 NAA (Treatment No. 2) or 2.0 mg·L−1 6-BA and 0.2 mg·L−1 NAA (Treatment No. 3) or Treatment No. 6. Conclusion The WPM medium with 2.0 mg·L−1 6-BA and 0.1 mg·L−1 IBA delivered the highest germination rate of the semi-abortive seed embryos among all treatments. The germination of the intact embryos was found always higher than that of semi-abortive embryos. And, without added plant growth regulators, the WPM or MS medium could, nonetheless, provide acceptable embryo germination for Younai seeds.
2020, 35(3): 309-316.
doi: 10.19303/j.issn.1008-0384.2020.03.010
Abstract:
Objective Varied N levels for fertilization were applied to determine the effects on the morphological and physiological characteristics of the Juglans regia L. rootstock seedlings from two provenances in Xinjiang. Methods Juglans regia L. rootstock seedlings from provenances at Aksu and Hotan were treated with varied levels of N fertilizer, and the morphology, biomass, photosynthetic characteristics, and soluble sugar content in leaves of the seedlings determined. Results The various evaluation indicators tended to increase initially and followed by a decline upon increasing N but responded differently between the seedling specimens from the two localities. Under 10−15 g·a−1·plant−1 application rates, the plant height peaked at 95.27 cm and 72.07 cm, while the total root volume at 1 249.75 cm3 and 928.01 cm3, respectively, for the Juglans regia L. plants from the two sources. The net photosynthetic rates for them increased with N to arrive at a maximum of 12.725 1 μmol·m−2·s−1 and 12.357 3 μmol·m−2·s−1, respectively, under the 10 g·a−1·plant−1 fertilization. Further increases on N caused a gradual decline on the net photosynthetic rate. According to the comprehensive evaluation, the morphological characteristics and physiological characteristics of Juglans regia L. rootstock seedlings in the two provenances with nitrogen application at 10−15 g·a−1·plant−1 showed the optimal characters. Conclusion Over all, the Juglans regia L. rootstock seedlings from the two provenances performed well morphologically and physiologically under the applications of 10−15 g·a−1·plant−1. In that range, Aksu walnut exhibited a greater N utilization ability than its counterpart.
2020, 35(3): 317-322.
doi: 10.19303/j.issn.1008-0384.2020.03.011
Abstract:
Objective Dissipation of two new insecticides and risk of the residues in tea and soil were studied. Method A gas chromatographic method was applied for analyzing nitenpyram and tolfenpxrad residues in tea and soil specimens to determine the dissipation and transfer of the insecticides after application. Result The insecticide residues in tea and soil decreased exponentially with time after application in a first-order kinetic function. The half-lives of nitenpyram at the recommended dosage were 6.08–6.54 d in tea and 1.52–1.68 d in soil. It took 0.91–3.33 d for the residue to degrade below the maximum allowable residue limit (MRL) in tea. For tolfenpxrad at the recommended usage level, the residue half-lives were 4.47–4.74 d in tea and 1.87–1.89 d in soil. It took 5.10–8.18 d for the pesticide residue to dissipate below MRL in tea. Conclusion Both nitenpyram and tolfenpxrad were found to degrade to below the MRLs in tea for safe consumption as well as in soil for environmental protection.
2020, 35(3): 323-330.
doi: 10.19303/j.issn.1008-0384.2020.03.012
Abstract:
Objective The loss control urea (LCU) that, when dissolved in water, couples in a network structure to mitigate ammonia volatilization and N leaching in rice field fertilization was studied for its practical applications. Method A plot experiment in the field was conducted with varied applications of LCU to determine the resulting rice yield and N utilization efficiency (NUE) as well as the N loss through leaching. In addition to control without N fertilization (CK), the treatments included applications of the conventional urea (CU), recommended LCU usage, 10% reduced LCU usage, 20% reduced LCU usage, LCU/CU at 7 ﹕ 3 ratio, LCU/CU at 5 ﹕ 5 ratio, LCU/CU at 3 ﹕ 7 ratio, and LCU by basal application. Result (1) All LCU applications improved the rice yield over CK. The largest increase of 8.92% over CU was resulted from the mixture of LCU/CU at 5 ﹕ 5 ratio. LCU/CU at 7 ﹕ 3 mixing ratio produced the second highest yield gain. The gains on rice yield was mainly attributed by the increase of the grain count per panicle. (2) LCU significantly improved NUE of the rice plants. By reducing 10% on the LCU usage, the highest NUE with an increase of 9.79 over CU was observed among all applications. That was followed by the second highest delivered by LCU/CU at 5 ﹕ 5 ratio. (3) LCU significantly reduced the total N concentration in surface water and N loss from leaching. In comparison to CU, depending upon the application rate, LCU reduced 28.40%–66.32% of the N loss from leaching in an entire rice growth period. By reducing 20% on the LCU usage, the highest N loss from leaching reduction was observed, followed by 10% reduced LCU usage, and then the CU treatment. Conclusion LCU significantly improved the yield and NUE of rice plants and reduced the N loss from leaching in soil. The application of LCU at 243–270 kg ·hm−2 N with a 5 ﹕ 5 mixing ratio with CU was recommended for the rice farming in the Yellow River irrigation region.
2020, 35(3): 331-336.
doi: 10.19303/j.issn.1008-0384.2020.03.013
Abstract:
Objective Phsicochemical properties of composts with varied nitrogen (N) contents during tunnel composting were analyzed to provide the basis for optimizing the formula of Agaricus bisporus substrate. Method Wheat straws and chicken manure were blended to result in starting compost materials with varied N contents at 1.15% (T1), 1.35% (T2), and 1.55% (T3) for the tunnel composting. Samples at different composting stages were taken for measurements on moisture, ash, and N contents as well as pH. Yields of mushrooms grown on the composts from Phase Ⅰ and Phase Ⅱ of the composting process were compared for evaluation. Result In all cases, the N content in compost increased continuously during the fermentation process. Collected after Phase Ⅱ, the 2.28% of N content from T3 was significantly higher than T1. The generally weak alkaline compost had a pH increased initially followed by a decline. The pH of T3 in either Phase Ⅰ or Phase Ⅱ was the highest among all samples. A correlation between the pH and N content in compost was observed. The moisture content decreased continuously during the fermentation showing a minimum at 65.78% on T3 in Phase Ⅱ which was considered suitable for the mushroom cultivation. The ash content increased continuously along the composting. Among the various N levels, T1 had the lowest ash content at the beginning and remained the lowest with a content of 30.92% at the end of Phase Ⅱ. The compost with a higher N content during tunnel composting produced higher mushroom yield, as the greatest yield of 20.74 kg·m-2 was found on T3. Conclusion The physicochemical properties of the compost during tunnel composting changed significantly with varied N contents in the raw material. The mushroom yield reached the highest level under T3 when 1.55% N was formulated in the starting compost materials. Thus, T3 was recommended for commercial A. bisporus cultivation.
2020, 35(3): 337-343.
doi: 10.19303/j.issn.1008-0384.2020.03.014
Abstract:
Objective Effects of intercropping peanut (also as green fertilizer) on soil and microclimate at banana orchards were studied. Method Five different planting practices at a banana orchard were implemented for comparison. They included CK (banana monoculture as control), Method A (3 rows of 2-peanuts-sowing for intercropping with banana followed by mulching with the plant waste), Method B (3 rows of 2-peanut-sowing for intercropping with banana followed by turning the plant waste into field soil), Method C (5 rows of one-peanut-sowing for intercropping with banana followed by mulching with the plant waste), and Method D (5 rows of one-peanut-sowing for intercropping with banana followed by turning the plant waste into field soil). Effects of the various seeding/waste treatments on the physiochemical properties of soil and microclimate at the orchard as well as the banana/peanut yields and quality were determined. Result Method C was found to perform with the highest scores on the major evaluation criteria among all. The banana seedling height, stem circumference and green leaf count were 89.74%, 11.89% and 32.05%, respectively, greater than those under CK. With respect to the microclimate, Method C increased the surface humidity by 4.61%, decreased the ground temperature by 2.07%, and lowered the air temperature by 8.39%, as compared with CK. Furthermore, it also reduced the weed growth by 84.62% and the banana plant damage rate by 65.21%. The contents of available N, P, K, Ca, and Mg in the orchard soil were significantly increased by 17.18%, 6.17%, 76.01%, 63.58%, and 34.59%, respectively, while the organic matters significantly increased by 25.15% under Method C over CK. Among the enzymes in the soil, the activity of invertase was 2.38 times of that under CK at an extremely significant different level; and, those of urease, acid phosphatase, catalase, and cellulase 44.27%, 75.92%, 13.94%, and 11.58%, respectively, higher than those under CK. Method C also resulted in a rise on the percent soil aggregates with a size larger than 2mm from 22.0% under CK to 35.22%. Moreover, the treatment produced bananas with increases on yield of 2.31%, on soluble sugar of 15.21%, on VC of 5.10%, and on soluble solids of 8.73%. Conclusion It appeared that by intercropping banana plants with peanut bushes followed by mulching the ground with peanut plant wastes could significantly improve the structure, fertility, and enzymatic activities of the soil as well as the microclimatic conditions, such as temperature and humidity, at the orchard. In the end, besides the ecological benefits, the practice would promote the banana growth, reduce the pest infestation, and weed proliferation, as well as improve the crop yield and quality for the orchard operation.
2020, 35(3): 351-358.
doi: 10.19303/j.issn.1008-0384.2020.03.016
Abstract:
Camellia oleifera is a crop for food oil in China that constitutes an important part of the economic vegetation and bio-energy source in the southern regions. Being only moderate drought-resistant, C. oleifera can be vulnerable to the stress of water deprivation, especially during its growing and developing periods. The ill-effects brought about by the stress may include growth retardation and yield decline resulting in financial losses to the farmers. Consequently, studies to understand and mitigate the stress-induced hazard is of interest to the scientists and agricultural professionals. This article summarizes the publications on the mechanisms involving C. oleifera in dealing with drought-stress. The morphological adjustments, physiology responses, and drought relief of the plants and the measures current available and under study for the stress alleviation as well as suggestions for future research are presented.
Camellia oleifera is a crop for food oil in China that constitutes an important part of the economic vegetation and bio-energy source in the southern regions. Being only moderate drought-resistant, C. oleifera can be vulnerable to the stress of water deprivation, especially during its growing and developing periods. The ill-effects brought about by the stress may include growth retardation and yield decline resulting in financial losses to the farmers. Consequently, studies to understand and mitigate the stress-induced hazard is of interest to the scientists and agricultural professionals. This article summarizes the publications on the mechanisms involving C. oleifera in dealing with drought-stress. The morphological adjustments, physiology responses, and drought relief of the plants and the measures current available and under study for the stress alleviation as well as suggestions for future research are presented.
