2022 Vol. 37, No. 11
Display Method:
2022, 37(11): 1371-1380.
doi: 10.19303/j.issn.1008-0384.2022.011.001
Abstract:
Objective Purifying and cross-matching the male line D of Cyan-shank Partridge chickens were studied to sustain a desired appearance and performance for commercial breeding. Method Using PCR, the breeder cocks with TYR heterozygous genotype were eliminated to achieve feather color selection, disease eradication, body weight, and egg laying. A synthesized D line was obtained by pure breeding for 3 generations, and then, employed as the terminal male parent for performance testing on a 3-line crossing. Result （1）A consistent feather color on the D line was reached by eliminating the heterozygote of TYR gene in the cocks from generation 1 (G1) to generation 3 (G3). The proportion of white feather on the cocks decreased from 50.49% in G1 to 1.89% in G3. Through the phenotypic selection, the proportion of chickens with wild-quail-like feather increased from 21.12% in G1 to 93.78% in G3. （2）A significant result on the pullorosis eradication in each generation was realized with a positive disease rate reduced from 14.6% in G1 to 2.4% in male D3, and from 6.83% in G2 to 2.08% in female G3 chickens.（3）The body weights of the 43-week-old G3 roosters and hens were 3 993.70 g and 3 397.14 g, respectively, being 174.64 g and 67.6 g, respectively, heavier than G1 counterparts (P＞0.05). Those hens laid 60.3 eggs per week with an average weight of 63.38 g per egg in G1 increasing to 82.5 eggs per week with an average weight of 64.42 g in G3. The average generation-to-generation improvements were 12.27% on egg production and 1.64% on egg weight. （4）D♂× (K♂×Y♀) produced a breed more productive in meat than the other 4 crosses. In 80 d, the average body weights of the DKY male and female broilers reached 2992.46 g and 2395.7 g, the half-eviscerated percentage of 85.57% and 85.27%, and the pectoral muscle percentage of 19.19% and 21.56%, respectively. Conclusion After 3 generations of breeding, the appearance and meat productivity of the paternal D line Cyan-shank Partridge chickens had been greatly improved for the commercial breeding.
2022, 37(11): 1381-1387.
doi: 10.19303/j.issn.1008-0384.2022.011.002
Abstract:
Objective A Method Specific primers and probes labeled with FAM and VIC were designed to amplify the N gene of PEDV and the S gene of TGEV, respectively. A reaction system for the assay was established, optimized, and tested for sensitivity, specificity, and repeatability. The assay was used for the viral detection on 297 suspected clinic specimens collected from 2019 to 2021 for an epidemiology study. Result The newly developed duplex qPCR methodology showed a sensitivity of 10 copies·μL−1 on PEDV and TGEV, which was 100 times higher than that of regular PCR. There were no cross reactions with other common viruses. The inter- and intra-assays had variations on Ct values below 1%. On the 297 specimens, the infection rate of PEDV was 88.89%, that of TGEV 1.01%, and that of both PEDV and TGEV 3.37%. Conclusion The established duplex qPCR had high sensitivity, specificity, repeatability, and reproducibility for detecting PEDV and TGEV. The 2019–2021 epidemic involving the viruses appeared to be mostly PEDV with low incidents of mixed TGEV and PEDV/TGEV infection.
2022, 37(11): 1388-1393.
doi: 10.19303/j.issn.1008-0384.2022.011.003
Abstract:
Objective Epidemiology and genetic variations of the infectious bronchitis virus (IBV) in Fujian province were studied. Method Two strains of virus isolated from the diseased chickens in Fujian in 2021 were identified by chicken embryo pathogenicity test, electron microscope observation, and RT-PCR. S1 genes of the isolates were cloned, sequenced, and analyzed using biological software. Result The two IBV strains were code named FJ-NP01 and FJ-FZ01. The full length of S1 of FJ-NP01 was 1629 nt encoding 543 amino acids, and that of FJ-FZ01, 1620 nt encoding 540 amino acids. The S1 gene cleavage site of FJ-FZ01 was HRRRR, same as all reference strains of genotype I branch; while that of FJ-NP01 HRRKR differed from the reported site of IBV isolated from genotype Ⅳ but same as that of TC07-2 reference strain of genotype Ⅵ. The homology of nucleotide and amino acid between the two isolates was 83.2% and 79.6%, respectively, but merely 75.7%–76.3% and 77.1%–83.5% with the Mass-type conventional vaccines H120 and H52, respectively. Further analysis showed that FJ-NP01 was from a recombination event between CK CH GD LZ12-4 and L-1148, the homology of nucleotide acid between 1438–1506 nt of FJ-NP01 with CK CH GD LZ12-4 was 97%, and 95.9% between the other nucleotide acid of S1 gene with L-1148 . Conclusion It appeared that the IBV epidemic experienced in the province was complex in nature and that the existing Mass vaccines would not provide sufficient immune protection to deter the spread.
2022, 37(11): 1394-1399.
doi: 10.19303/j.issn.1008-0384.2022.011.004
Abstract:
Objective The aim of the present study was to establish a duplex PCR method for detection of Anguillid herpesvirus and Eel circovirus. Method Routine PCR primers were preferred to optimize the amplification conditions and test the specificity and sensitivity of the method. At the same time, the sick eel of suspected cases collected from different farm were detected by the duplex PCR method, and compared with the routine PCR method. Result The results showed that the specific fragments of 690 bp and 388 bp were amplified by using the duplex PCR from DNA samples of Anguillid herpesvirus and Eel circovirus, respectively. But the nucleic acid amplification results of Porcine circovirus, Duck circovirus, Koi herpesvirus and Cyprinid herpesvirus were negative. When the positive DNA concentrations of both Anguillid herpesvirus and Eel circovirus were diluted to 5.0×10-4 μg·mL-1, the corresponding target fragments could still be detected. 50 samples collected from suspected cases of sick eels were diagnosed by PCR. The infection rate of Anguillid herpesvirus was 16%. The infection rate of Eel circovirus was 68%. The infection rate of Anguillid herpesvirus and Eel circovirus was 8%. Conclusion The results indicate that the duplex PCR detection method has certain specificity and sensitivity, and can be used for the detection and differential diagnosis of recessive cases of clinical infection of Anguillid herpesvirus and Eel circovirus．
2022, 37(11): 1400-1406.
doi: 10.19303/j.issn.1008-0384.2022.011.005
Abstract:
Objective Epidemiology and mechanism of quinolone-related drug resistance genes of Riemerella anatipestifer found in ducks in Putian, Fujian were investigated. Method The K-B method was applied to examine 55 strains of R. anatipestifer to determine their resistance to 6 types of quinolones. PCR was employed to detect and analyze the quinolone resistance determining region (QRDR) and plasmid mediated quinolone resistance (PMQR) genes. Result More than half of the 55 strains examined were multi-resistant and highly resistant to pipemidic acid, norfloxacin, enrofloxacin, and ciprofloxacin; and more than 90% of them highly sensitive to ofloxacin. PCR did not find the 4 PMQRs, i.e., qnrA, qnrB, qnrS, and oqxA, in the specimens. On the other hand, 6 QRDR mutations in the deduced amino acid sequences of gyrA, including S83R and S83I, S84P, D87A and D87G, A183V, N202E, and Y211H were detected. Among them, S83I, N202E, and Y211H had the highest mutation rates of 98.18% (54/55), 92.73% (51/55), and 90.91% (50/55), respectively. Of which, the S83I (38/39) and S83R (1/39) mutations were found in gyrA of 39 enrofloxacin-resistant strains, and the S83I mutations also in that of 3 enrofloxacin-sensitive strains. There was only one enrofloxacin-intermediated strain that had the F155S mutation in parC, which was not previously reported to exist in R. anatipestifer. Conclusion The quinolone-resistance of R. anatipestifer found in ducks in Putian was severe. No PMQR was detected in the samples, but the S83I mutation in gyrA of QRDR could be the major culprit that involved in the drug resistance of R. anatipestifer.
2022, 37(11): 1407-1414.
doi: 10.19303/j.issn.1008-0384.2022.011.006
Abstract:
Objective Effects of a forage with reduced protein and a supplement of essential amino acids, glutamate, and arginine on the growth, diarrhea rate, and serum indicators of weaned piglets were studied. Method One-hundred-ninety-two healthy (26±2)-day-old crossbred piglets (Duroc × Landrace ×Large White) were randomly divided into a control and 3 treatment groups. Each group comprised 6 replicates of 8 piglets. They were fed for 16 days with the following forages containing 21.16% crude protein (CP) as control (Group 1), low-protein of 15.97% CP supplemented with the essential amino acids including L-Lys, DL-Met, L-Thr, L-Thr, L-Val, and L-Ile (Group 2), 15.93% CP with the same added essential amino acid plus 1.5% glutamate (Group 3), and 15.95% CP with the added essential amino acids plus 1.5% glutamate and 1.0% arginine (Group 4). At end of the feeding, body weight, forage consumption, number of days with diarrhea, and blood samples of the piglets were collected for daily gain, feed to weight ratio, diarrhea rate, and plasma biochemicals and hormones determinations. Result The average daily weight gain (ADG) of the piglets in Group 2 was significantly lower than those in other groups (P＜0.05). There were no significant ADG differences among those 3 groups, nor the average daily feed intake (ADFI) among all groups (P＞0.05). The feed/gain (F/G) of Group 2 was significant higher than other groups (P＜0.05). The diarrhea rate of Group 2 piglets was significantly lower than that of Group 1; Group 3 and Group 4 extremely significantly lower than that of Group 1; and Group 3 and Group 4 significantly lower than that of Group 2 (P Conclusion The reduction of CP to 15.97% in forage could adversely affect the growth as well as the intestinal barrier permeability to varying degrees of the weaned piglets. However, it also reduced the diarrhea rate and plasma PUN of the weaned piglets. Since the addition of glutamate in diet restored the growth and improved the levels of gastrointestinal hormones of piglets, feeding piglets an essential amino acid-balanced, low-protein diet with the supplementation of glutamate could be a plausible strategy to mitigate the occurrences of diarrhea and interference on the intestinal mucosal barrier permeability in the animals after weaning.
2022, 37(11): 1415-1429.
doi: 10.19303/j.issn.1008-0384.2022.011.007
Abstract:
Objective Sequences and functions of banana GDSL lipase gene family (MaGDSL) were studied. Methods Bioinformatics was applied to identify the genomes, analyze the distributions of chromosomes, promoter cis-acting elements, and transcription factor binding sites (TFBS), and determine the physicochemical properties, gene structure, conserved motifs, and phylogenetic relationships of the encoded proteins of the MaGDSL family. Based on the transcriptome database, the expressions of MaGDSLs in the high (45 ℃)- or low temperature (4 ℃)-treated leaves, FocTR4-infested roots, and the natural or ethylene ripened fruits were measured. And qRT-PCR was employed to obtain the expressions of MaGDSL members in pollen. Results The banana A genome had 76 MaGDSLs of 9 subfamilies distributed on 11 chromosomes. The coding region of each member was 1014–2193 bp. Five of the members contained varied number of transcripts, but most of them had 5 exons and 4 introns. The encoded proteins had signal peptides localized mainly in the inner and outer membranes. The MaGDSLs had 3 tandem repeat clusters on chromosomes 4 and 8, 6 tandem repeat pairs on chromosomes 1, 6, 7, 8, 9, and 10, and 22 fragment repeat pairs on all except chromosome 11. The expressions of MaGDSLs in banana leaves and roots were highly variable with individual members regulated by high and low temperature stresses as well as the blast fungus. Five members (i.e., MaGDSL4-5, 8-1, 8-12, 9-4, 9-5) were repressed, but MaGDSL2-1 and MaGDSL6-8 induced, by high- or low-temperature exposure, while MaGDSL4-1 and MaGDSL11-1 regulated by low temperature and FocTR4, MaGDSL5–8 responded only to low temperature, MaGDSL2-2 and MaGLP10-5 sensitive to various treatments, and MaGDSL1-1 highly expressed in the roots and pollens. Conclusion MaGDSLs might play an important role in the growth and development of banana plants. Some of the members responded specifically to certain biotic and/or abiotic stresses.
2022, 37(11): 1430-1437.
doi: 10.19303/j.issn.1008-0384.2022.011.008
Abstract:
Objective The squalene synthase (SQS), the first key rate-limited enzyme in the triterpenoids biosynthetic pathway, from Clematis florida Thunb. var. plena D. Don was cloned, and its expression analyzed in preparation for an investigation to increase the medicinal value of the plant by means of genetic engineering. Method Primers were designed based on the transcriptome data on the SQS genes in C. florida and in other plants. Total RNA was extracted from C. florida leaves, and full-length cDNA obtained by RT-PCR. Bioinformatics and spatiotemporal expression of the gene were analyzed. Result The ORF of the SQS, designated as CfSQS, was 1 227 bp encoded 408 amino acids. It was an unstable hydrophobic protein comprised 69.61% of α helix and 22.06% of random coil. The deduced amino acid sequence predicted the presence of 4 highly conserved domains with 17–23 amino acids residues (I–IV) and one variable hydrophobic region (V). The predicted 3D structure of CfSQS by various programs was similar to those of SQSs from other species. It had a close phylogenetic relationship and in the same clade with the SQS of Nigella sativa. A spatiotemporal expression analysis indicated the gene to be expressed in all tissues. Conclusion The full-length cDNA sequence and bioinformatics of the squalene synthase gene CfSQS of C. florida were determined for the first time. The information helped to further clarify the synthesis of the saponin compounds and regulatory mechanism that would pave the way for future studies on the biosynthetic pathways of triterpene saponins in C. florida.
2022, 37(11): 1438-1447.
doi: 10.19303/j.issn.1008-0384.2022.011.009
Abstract:
Objective Effect of elevated temperature and drought stresses on the content of endogenous hormones in jujube fruits was studied. Method In a simulated experiment, 6-year-old Zipiphus jujuba Mill cv. Lingwuchangzao plants were artificially exposed to varied temperatures and restricted water supplies. Ambient atmosphere temperature (T1) and one of 2oC above it (T2) were applied in combination with a simulated water supply for normal condition in soil (D1), moderate drought (D2), or severe drought (D3). Contents of endogenous hormones (i.e., IAA, ABA, ZT, and JA) in the jujube fruits born from the trees at 7 ripening stages were determined. Result The interactive effect on the hormones by the simulated temperature and drought conditions was significant (P＜0.05). The contents of ABA, IAA, and JA in the fruits were higher when the atmospheric temperature was raised 2 ℃ above normal. Those of ABA, ZT, and JA also became greater under D2, but that of IAA lower, than D1; whereas those of ABA and JA, increased and those of IAA and ZT, decreased under D3. Conclusion The slightly elevated temperature by 2 ℃ seemed to benefit the accumulation of IAA and JA in the jujube fruits, while the drought stress accentuated the temperature effect on the contents of IAA and JA. Water deprivation appeared to benefit ABA and ZT accumulation, and temperature elevation by 2 ℃ promoted the accumulation of ABA but hindered that of ZT.
2022, 37(11): 1448-1453.
doi: 10.19303/j.issn.1008-0384.2022.011.010
Abstract:
Objective Effects of the target of rapamycin (TOR) inhibitor rapamycin on the growth, development, pathogenicity, and autophagy of Peronophythora litchi were studied. Method The mycelial growth, sporangial production, zoospore release, and pathogenicity of the P. litchi after being treated by the TOR inhibitor rapanmycin in varying concentrations were determined, while the mycelial autophagy observed under a microscope with MDC staining. Result Rapamycin exhibited significant inhibitory effect on the mycelial growth of P. litchii with an EC50 value of 29.18 ng·mL−1 and varying extents of increases with higher dosages. When treated with 25.0 ng·mL−1 rapamycin, the inhibition rate was 45.3% and the sporulation at 8.0×104 sporangia·mL−1 (which was 27.9% of control), while the zoospore release increased, but the virulence of P. litchii significantly reduced. The MDC-stained autophagosomes significantly increased as well. Conclusion The TOR signaling pathway inhibitor rapamycin played an important role in the mycelial growth, development, and virulence of P. litchii.
2022, 37(11): 1454-1462.
doi: 10.19303/j.issn.1008-0384.2022.011.011
Abstract:
Objective Effects of acid electrolyzed oxidizing water (AEOW) treatment on the microorganisms on the surface and germination of maize seeds and seedling emergence were investigated. Method Seeds of the major varieties cultivated in Fujian, Taixiantian No. 1 and Taixiantian No. 2, were mixed with AEOW. Microbial counts on the seed surface and in the surface rinse, rates of infection, seed germination, and seedling emergence as well as seedling fresh weight were determined. Result AEOW significantly inhibited the microbial growth on the seed surface as indicated by the counts in the seed surface rinses and the AEOW/maize seeds mixtures. The suspension of AEOW/seed rinse at 1︰2 (mL/mL) ratio had a count of 0.44 cfu·mL−1 in comparison to more than 10 000 cfu·mL−1 of CK. In the liquid after 6 h submerging the seeds in AEOW at the ratio of 125︰2 (mg/mL), the count was nil. On the seed infection rates, the rinse was 14.00% and the mixture liquid 7.33% in comparison to control of 100%. The frequency of bacterial appearances on the treatment seeds was 1.33% and that of fungal, 20.00%, largely Fusarium spp. As for the safety concerns, the AEOW-treated Taixiantian No. 1 seeds increased on germination rate by 13.33%, bud length by 0.32 cm, main radicle length by 0.73 cm, and radicle number of seeds by 0.16, while the treated Taixiantian No. 2, by 8.66%, by 0.55 cm, by 0.42 cm, and by 0.07, respectively. The treated seeds of with a Fusarium verticillium pre-inoculation increased on germination rate, bud length, main radicle length, and radicle number of Taixiantian No. 1 and Taixiantian No. 2 seeds by 17.04% and 6.67%, 0.54 cm and 0.33 cm, 1.89 cm and 0.40 cm, 0.60 and 0.26, respectively; and those with a Pseudomonas spp. pre-inoculation, by 35.34% and 28.66%, 0.85 cm and 0.30 cm, 2.30 cm and 1.70 cm, 0.76 and 0.36, respectively. The seedling emergence rates of the two treated maize varieties increased by 5.33% and 8.00%, respectively, but not significantly differed between them and control with respect to plant height and shoot fresh weight. Conclusion The AEOW treatment effectively inhibited the presence and growth of microbes on maize seed surface with a more pronounced effect on bacteria than on fungi. The treatment benefitted and was safe for germination and seedling emergence of the AEOW-disinfected seeds.
2022, 37(11): 1463-1469.
doi: 10.19303/j.issn.1008-0384.2022.011.012
Abstract:
Objective A biocontrol microbe on Thosea senensis Walker suitable for organic tea agriculture was identified and optimal culture conditions studied. Method From the intestines of T. senensis died from disease in nature, microbes were cultured and screened by means of varying the temperature. Indoor virulence of the selected microbes on T. senensis was determined by immersion feeding and further identified by morphological, molecular biological, and phylogenetic tree analyses. Culture of the isolated strain was optimized by univariate and orthogonal experiments. Result The endophytic strain X-11 with high efficacy in controlling the pest was isolated. The 3rd instar larvae of T. senensis fed with a 2.56×108 conidia·mL−1 X-11 solution displayed a cumulative corrected mortality rate of 90.5% with a median lethal time LT50 of 2.88 d on the 7th day after treatment. Based on the 16S rDNA molecular identification and phylogenetic analysis, X-11 was determined to be Paenibacillus azoreducens. The optimized culture conditions for the bacterium included the use of 2% inoculum to culture for 60 h at 36℃ with a final count approaching 1.34×109 conidia·mL−1. Conclusion The endophytic strain with high control efficacy on T. senensis larvae was identified as P. azoreducens. It could be cultured to be used as a bioagent for the pest control at tea plantations.
2022, 37(11): 1470-1475.
doi: 10.19303/j.issn.1008-0384.2022.011.013
Abstract:
Objective A loop-mediated isothermal amplification (LAMP) method for visual, rapid, and accurate detection of Diaporthe citri on pomelos in early stage of black spot disease was developed. Method Based on the elongation factor-1α (EF-1α) sequence of D. citri, a set of LAMP primers was designed. Template DNA from the infected leaves was used to establish the optimal temperature and time for the LAMP operation. Assay specificity and sensitivity were verified by positive detection of the infected plants in the field. Result The newly established LAMP method could effectively and specifically detect D. citri on pomelo at the optimal temperature of 65 ℃ with 60 m for the reaction time. The detection limit of the assay on D. citri was 10 fg·μL−1. On 15 field samples with the typical black spot symptoms, a 100% positive detection rate was achieved by the LAMP assay. Conclusion The established visual and rapid LAMP assay demonstrated a high specificity, sensitivity, and perfect detection of D. citri on diseased pomelo. It was considered appropriate for field application.
2022, 37(11): 1476-1482.
doi: 10.19303/j.issn.1008-0384.2022.011.014
Abstract:
Objective Effects of combined application of organic and chemical fertilizers on the bacterial community in soil of banana plantations were studied. Method Various proportions of chemical fertilizer combined with an organic fertilizer, as well as all or reduced chemical fertilizer, were mixed in the soil from a banana plantation to determine the effect of the applications on the bacterial community in soil. The treatments included the uses of no fertilizer as control (T1), 25% chemical fertilizer (T2), 50% chemical fertilizer (T3), 100% chemical fertilizer (T4), and 50% reduced chemical fertilizer without organic fertilizer (T5). 16S rRNA genes of the bacteria were analyzed by Illumina MiSeq high-throughput sequencing. A bioinformatic analysis was performed to determine the structure, abundance, and diversity of the bacterial communities in soil under treatments. Result The OTUs of the T1, T2, T3, T4, and T5 treatments were 30, 33, 31, 34, and 31, respectively. The proportion of beneficial bacteria in the soils varied by the treatments. The relative abundances of beneficial proteobacteria and acidobacteria were increased by the treatment of T3. The Shannon index of the bacteria in soil under different treatments ranked as T3＞T5＞T2＞T1＞T4. In comparison to T5, T3 improved and T2 reduced the soil bacterial diversity indicating a disadvantage of the reduced use of chemical fertilizer. However, the lowest diversity was observed under T4 which showed excessive chemical fertilization to be detrimental, nonetheless. The PCoA and heat map analyses revealed significant changes on the bacterial compositions, relative abundance, and beneficial bacteria in the soil by the treatments. Conclusion Comparing to the use of chemical fertilizer alone, appropriate combination of organic and inorganic fertilizers effectively improved the bacterial diversity and composition in soil. A 50% reduction of chemical fertilizer usage coupled with organic fertilizer (T3) could not only conserve the chemical fertilizer, but also enhance the relative abundances of beneficial bacteria and bacterial diversity resulting in an improved soil fertility.
2022, 37(11): 1483-1492.
doi: 10.19303/j.issn.1008-0384.2022.011.015
Abstract:
Objective Temporal and spatial characteristics of the culturable fungal community in a GORE cover membrane system (GCMS) for composting agricultural waste were analyzed to evaluate and enhance the utilization of the treatment system. Methods In a GCMS tank fermentation on agriculture waste material, temperature was continuously monitored, and varied temporal and spatial samples collected for microbial determination. Culturable fungi in the system were isolated, identified, and counted for analyzing and calculating spatial distribution pattern index, diversity index, and ecological niche characteristics. Results The average temperature of the composting material in the tank was 55.27-74.64 ℃ from the 2nd to the 16th day, which was defined as the high temperature period. In the low temperature period from the 17th to the 27th day, the average temperature was 41.26-50.64 ℃. From 72 specimens, 5 species of fungi, i.e., Mortierella walfii, Penicullium sp., Aspergillus fumigatus, Aspergillus spinosus, and Aspergillus terreus, were isolated and identified. Spatially, the population of A. fumigatus was the largest Conclusion The count of culturable fungi in GCMS differed significantly in different periods and locations. The spatial distribution of the fungal populations followed an aggregated pattern.
2022, 37(11): 1493-1502.
doi: 10.19303/j.issn.1008-0384.2022.011.016
Abstract:
Objective Means to utilize coffee peel waste and improve quality of ground soil at coffee plantations were investigated. Method The soil at a 56-year-old coffee plantation was used as the base material for the pot experiment. Aside from CK using 100% plantation soil, treatments applied the mass fractions of acid soil conditioner (TL) and fermented coffee peels (CP) including TL1 (2% TL), TL2 (4% TL), TL3 (6% TL), TL4 (8% TL), CP1 (4% CP), and CP2 (8% CP) were added to the potting soil. Leaf photosynthetic properties, and RuBP activity, growth indicators, and dry biomass accumulation of the seedlings, as well as nutrient content, pH, and activities of acid phosphatase (S-ACP), alkaline phosphatase (S-ALP), catalase (S-CAT), and urease (S-UE) in soil were determined. Result The addition of TL raised 0.8-1.6 on the soil pH, while CP increased it at first, then decreased, and became 0.50 lower than CK after 6 months. The available K and exchangeable Ca and Mg in soil were significantly increased with increasing TL or CP. But the available P significantly dropped by the added TL which, at TL4, was 69.34% lower than CK. The total N, alkaline N, and available P were significantly higher with CP than other treatments. TL2 and TL3 showed the greatest effects on RuBP enzyme activity with significantly 101.16% and 135.30%, respectively, and on net photosynthesis (Pn) 81.71% and 80.35%, respectively, higher than CK. And those were followed by the treatments of CP1 and CP2. All enzyme activities in the soils treated by TL and CP were higher than CK, except ACP, which was similar to CK. The S-ALP activities in the treatment soils were 2.05 to 3.71 times higher than CK. The S-CAT activities were higher than CK by 109.62%-18.60% in the order of CP2＞CP1＞TL4＞TL3＞TL2. The S-UE activities were 18.70%-5.37% higher than CK with the highest showing under CP2 and CP1 followed by TL1 and TL4. The TL2, TL3, CP1, and CP2 treatments promoted the growth and dry matter accumulation of coffee seedlings with plant height and stem diameter increases by 25.09%-81.29% and total and dry weights of leaves, roots, and stems by 1.65-5.02 times over CK. Among them, CP1 delivered the greatest rises. Conclusion Application of TL and CP improved the soil microbial environment, increased the availability of soil nutrients, and promoted the coffee seedling growth. However, excessive TL could bring about high exchangeable Ca inducing P fixation, and with CP addition, the mineralization of organic N would lower the pH in soil. Consequently, the appropriate use of TL and CP was expected to achieve the goal of improving acid soil quality, utilizing coffee waste, and enhancing coffee cultivation at the plantations.
2022, 37(11): 1503-1508.
doi: 10.19303/j.issn.1008-0384.2022.011.017
Abstract:
Objective A new high-quality, high-yield, heat- and cold-tolerant Azolla with broad-adaptability was bred. Method Minyu 1 was bred by interspecies crossing male parent A. filiculoides 1001 and female parent A. microphylla 4018. Result After being screened at the variety comparison test and the regional and field trials conducted from 2001 to 2015, Minyu 1 was registered by the Chinese Herbage Cultivar Registration Board in 2015. It demonstrated an average hay yield of 88 209 kg·hm−2, which was significantly 158.3% higher than 34 146 kg·hm−2 exhibited by the reference variety, A. imbricata 500, 30.9% significantly higher than that of the parent, A. filiculoides 1001, at 67 398 kg·hm−2, and 30.9% significantly higher than that of the parent, A. microphylla 4018, at 71 738 kg·hm−2 (P＜0.01). It was also stable in maintaining the high yield performance. The nutritional content (dry matters) of Minyu 1 included 26.3% of crude protein, 16.0% of crude fat, 11.2% of crude fiber, 13.6% of crude ash, 36.9% of acidic detergent fiber, and 50.3% of neutral detergent fiber. Conclusion Minyu 1 had a short generation cycle, high yield, and strong cold- and heat-resistance suitable for cultivation in the country. The optimal temperature for its growth was 10-30 ℃. It could be used as green forage for raising fish, cattle, pigs, chickens, ducks, geese, and other animals, or as an aquatic green fertilizer in paddy fields as well.
