2019 Vol. 34, No. 2
Display Method:
2019, 34(2): 139-145.
doi: 10.19303/j.issn.1008-0384.2019.02.001
Abstract:
Objective Being one of the important agronomic traits that reflect the yield and physiological functions of a rice plant, the growth and photosynthesis of the fine hairs on the surface of rice leaves were studied. Method The sequences of GL6 gene promoters relating to leaf epidermal hair development were obtained and cloned from different rice varieties. That of Mutant 75-1-127 showing the characteristic epidermal hair development was compared with those of the wild type rice lacking it. The CDS sequence of the mutant gene was cloned. Then, the maize Ubiquitin and cauliflower mosaic virus CaMV35S were used as promoter-driven overexpression vectors to transform the wild-type Japonica rice, Kitaake, mediated by Agrobacterium. Result There were significant differences on the sequences in regions of the genes regulated by the promoters and cloned from different cultivars. The leaves of transgenic rice plants with GL6 driven by maize Ubiquitin promoter had significant hairy phenotype of the typical velvet appearance, but not those involved CaMV35S as a promoter. Conclusion It was clearly demonstrated that the promoters affected the expression of the target gene GL6 and that the epidermal hair development on leaves of Mutant 75-1-127 was derived by the promoter with a unique sequence.
2019, 34(2): 146-154.
doi: 10.19303/j.issn.1008-0384.2019.02.002
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Objective To improve efficiency and reduce waste on rice fertilization in the fields while protecting the environment, the upper limits on N, P and K applications for the farming of early rice, late rice, single cropping rice, rice after vegetable, and rice after tobacco in Fujian were studied. Method A total of 832 field experiments were conducted on (1) the early rice, late rice and single cropping rice in mountainous and coastal areas, (2) the after-tobacco cropping in mountain areas only, and (3) the after-vegetable cropping in either mountainous or coastal areas. System clustering analysis and significance test of difference were employed to classify the data generated. A ternary non-structural NPK fertilizer response model was then constructed for each category prior to field testing. Result Seven optimum fertilization categories for the early rice in the mountainous areas, 6 in the coastal areas, and 7 in the entire province were established. For the late rice, 6 in the mountainous areas, 4 in the coastal areas, and 7 in the entire province were obtained. For the single cropping rice, 6 in the mountainous areas, 4 in the coastal areas, and 6 in the entire province were resulted. And, for the after-tobacco cropping, 4 in the mountainous areas; while, for the after-vegetable cropping, 3 categories became available for analysis. Based upon these 60 models on the NPK fertilization limits set according to the agronomic effects on the rice plants, 234 field tests were carried out for final selection. It was verified that the formulations produced 4.0% to 12.5% increases on yield with an averaged net income increase from 875-2 616 Yuan·hm-2. In comparison to the common practice by the farmers, the recommended fertilizations reduced 19.4% on N usage and 23.9% on P but increased 27.3% on K2O. Conclusion The fertilization recommendations would optimize the fertilizer application with significantly improved efficiency for all types of rice cultivation currently practiced in the province.
2019, 34(2): 155-161.
doi: 10.19303/j.issn.1008-0384.2019.02.003
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Objective Enhancement on the growth, development and stress resistance of rice plants from the colonization of the endophytic fungus Piriformospora indica (Pi) on the roots was investigated. Method Pi was inoculated on 8 different media for optimal culture and co-cultured on rice seedlings to determine the biological improvements on the plants. Result Medium V8 was found to be most desirable for Pi growth. Addition of a certain amount of sucrose would further increase the effect. The plant height, leaf length, root length, root count, chlorophyll content and quality of the above- and underground parts of the treated rice plants were significantly greater than those of control. Notably, 20 days after the inoculation, the plant height increased by 32.36% and chlorophyll content 15.88%. Conclusion Pi significantly promoted the growth and development of rice plants as it symbiotically enhanced the photosynthesis and root physiology of the host.
2019, 34(2): 162-169.
doi: 10.19303/j.issn.1008-0384.2019.02.004
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Objective Effects of N and P additions on the growth and chlorophyll fluorescence indices of Polygonum multiflorum were studied to provide a guideline for proper fertilization to promote the plant growth. Method N and P addition, i.e., (1) N application using 2.7g urea/plant, (2) P application using 14.4g superphosphate/plant, (3) N+P application using 2.7 g urea and 14.4 g superphosphate on each plant, or (4) control without added N or P, was incorporated in the potting soil to observe the resulting growth and chlorophyll fluorescence indices of the plants. Result The treatments increased the leaf count, single leaf area, petiole length, and height of the plants in the order of N+P application > P application > N application > control. The addition of N+P significantly increased the biomass accumulation, proportion of above-ground biomass, and chlorophyll content as well as the indices of Fv/Fm, qP and ETR, with a decreased qN. Compared to control, N+P treatment affected the most on chlorophyll with a 96.08% increase and on qN with a 29.16% reduction. Conclusion Addition of both N and P in the potting soil significantly promoted the growth and photosynthesis of P. multiflorum.
2019, 34(2): 170-175.
doi: 10.19303/j.issn.1008-0384.2019.02.005
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Objective Morphological and physiological changes during flower bud differentiation of a Cymbidium hybrid were studied to decipher the floral formation mechanism. Method The process of flower bud differentiation of Golden Elf 'Sun-dust' was observed by means of paraffin section. The physiological indices, such as soluble sugars, starch and soluble protein, were measured at different stages of the differentiation. Result The differentiation process could be divided into 6 phases as undifferentiated and differentiations of inflorescence primordium, floret primordium, sepal primordium, petal primordium, and column and pollinia. During the process, the contents of soluble sugars and starch in the leaves fluctuated up and down; the soluble protein increased initially followed by a decline; and, the activities of POD and CAT decreased in the beginning and then increased. Conclusion The accumulations of soluble sugars, starch and soluble protein in the leaves prior to flower bud differentiation and the effective utilization at latter stages were found to significantly affect the differentiation process as well as the subsequent flower formation of Cymbidium hybrid.
2019, 34(2): 176-183.
doi: 10.19303/j.issn.1008-0384.2019.02.006
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Objective Molecular mechanism responsible for the formation of variegated succulent plants, Haworthia magnifica, was investigated using the mutant qj for the comparison. Method Contents of chlorophylls and carotenoids in the plants were determined by spectrophotometry, and gene expression by transcriptome sequencing (RNA-seq). Result The contents of chlorophyll a, chlorophyll b and carotenoids in the variegated qj were significantly lower than those of wild-type H. magnifica. Using RNA-seq, 44 988 938 Reads were obtained for H. magnifica and 37 271 576 for qj which were assembled into 45 226 Unigenes. There were 26 999 Unigenes assigned to Nr annotations, 20 279 to Swissport, 16 943 to KOG categories, and 10 775 to KEGG pathway. A total of 20 305 genes exhibited significantly different expressions that involved 130 pathways, of which 21 significantly differed from the others. The gene expression analysis showed that the genes associated with the chlorophyll synthesis (ko00860), antenna protein (ko00196) and photosynthesis (ko00195) pathways were generally significantly down-regulated. Conclusion The significant variations on the transcriptome sequences, genes and pathways of H. magnifica and its variegated counterpart obtained from this study provided the fundamental information for further study to unveil the underlaying mechanism.
2019, 34(2): 184-191.
doi: 10.19303/j.issn.1008-0384.2019.02.007
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Objective Effects of spraying plant growth inhibitors on the leaf diseases, early defoliation and reflorescence of pear trees were studied for improvements on prevention and control of the commonly occurred defects on pear trees in areas under hot and humid conditions. Method Five-year-old Cuiguan pear trees were sprayed with one of the 5 plant growth inhibitors or water (control) to observe the effects on the growth of shoots and leaves as well as the occurrence of leaf diseases, early defoliation and reflorescence. Result The chemicals applied controlled the growth of shoots in varying degrees ranking in the order of paclobutrazol > PBO > flusilazole > propiconazole > monopotassium phosphate. These inhibitors stopped shoot elongation 27.8 d, 15.2 d, 19.4 d, 18.8 d and 11.5 d, respectively, sooner than did control. On the leaves, paclobutrazol stimulated their growth, while the other chemicals exerted varying degrees of inhibitory effect on the growth. All inhibitors either significantly or extremely significantly alleviated the leaf diseases or delayed the early defoliation and reflorescence. The indices on 4 major diseases in various periods after treatments ranked in the order of flusilazole < PBO < propiconazole < monopotassium phosphate < paclobutrazol. The control effect of the inhibitors on early defoliation were in the order of flusilazole > PBO > propiconazole > monopotassium phosphate > paclobutrazol. The defoliation was delayed 25 d by flusilazole, 22 d by PBO, 20 d by propiconazole, 15 d by monopotassium phosphate, and 12 d by paclobutrazol. Conclusion Chemical control could be effective for leaf and flower retentions of a pear tree. Spraying combined agents might produce better effect.
2019, 34(2): 192-197.
doi: 10.19303/j.issn.1008-0384.2019.02.008
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Objective Grafting tomato scions on rootstocks of eggplant (Solanum torvum) was evaluated for its applicability. Method Plant growth, tomato yield and quality as well as fertilizer and water utilization of the seedlings grown on meteorite in a greenhouse from the Jinpeng No. 9 scions grafted on eggplant rootstocks were compared with those from the scions grafted on rootstocks of same variety (control). Result The S. torvum rootstock grafting retarded the plant height, leaf generation and weight gains on roots and stems of the grafted tomato seedlings but increased the root to shoot ratio, chlorophyll content and root activity. The individual weight, number per plant and yield per plant of the tomatoes decreased. The contents of Vc, soluble sugars and sugar/acid ratio of the fruits increased, while titratable acid decreased. No significant difference on the soluble solids and lycopene contents were observed between the seedlings grafted on S. torvum rootstocks and control. The water consumption and mineral absorption of the plants grafted on S. torvum rootstocks were less than those of control. Conclusion Overall, the growth, yield, quality and other indicators suggested that grafting tomato scions on S. torvum rootstocks would be suitable for application.
2019, 34(2): 198-203.
doi: 10.19303/j.issn.1008-0384.2019.02.009
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Objective The planting period, transplanting method and pollination time on the seedling growth of Siraitia grosvenorii plantlets were varied to investigate conditions for a high-yield cultivation practice. Method Five variations on planting periods, 4 on transplanting methods and 6 on pollination times were applied under 2 different weather conditions and 3 pollen storage methods for the experiment to determine the optimal conditions for the plantlet growth and development. Result Cracking of harvested S. grosvenorii nuts increased when planting was postponed in the season, especially if the planting was held in as late as early-June. A late-April planting was determined to be most desirable. The optimal seedling transplantation was conducted by transferring the seedlings from small nutrient pots to a large ones for greenhouse cultivation until mid-April when the weather became warmer. The plantlets were then transplanted to the field for latter stages of plant growth and fruiting. Pollination was best performed at 10 a.m. on a cool day. By storing in a 5-8℃ refrigerator the pollen vitality could be extended to 3 days. Conclusion Planting S. grosvenorii seedlings in northern Guangxi required an initial training stage to allow the plantlets grow in a greenhouse prior to field cultivation in between early-April and mid-May. That would better the climbing ability, budding, blossoming and yielding fruit early of the plants. The collected pollens should be stored at 5-8℃, and pollination be completed between 8 and 10 a.m. under cool weather.
2019, 34(2): 204-208.
doi: 10.19303/j.issn.1008-0384.2019.02.010
Abstract:
Objective Effect of seasonal synchronized estrus treatment on the reproductive performance of Fuqing goats was studied. Method PRID+PMSG+PGF2α was used on the goats to artificially induce estrous cycles in spring and autumn in a dry lot to determine the treatment effects. Result An average rate of estrus occurrence at 96.88% with an average conception rate of 93.75% was achieved in the goats by the treatment. During the trial, the lambs born by natural estrus mating (control) was fewer than those by the treatment. On the other hand, the number per delivery and body weight at birth of the lambs in control group were higher than those in the treatment group (P>0.05), but the treated goats had more lambs survived after weaned (P>0.05). The interval between births of the treated goats was significantly shorter than that of control (P < 0.01). As a result, there were 1.87 births annually with 3.12 survived baby lambs among the treatment goats representing 36.8% increase over control. Conclusion The preliminary results suggested that the artificial regulation on the estrus of Fuqing goats could increase the reproduction and survival rate of the new born lambs.
2019, 34(2): 209-213.
doi: 10.19303/j.issn.1008-0384.2019.02.011
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Objective Studying the pathogenicity of serotype O78 Escherichia coli to laying hens with different inoculation methods and the protective effects of single glycerides could provide theoretical support and practical experience for green no-antibiotic chicken breeding. Method The virulence of serotype O78 avian pathogenic Escherichia coli (APEC) strain isolated from a chicken farm in Fujian province was evaluated by oral, subcutaneous and intratracheal inoculation, and the protective effect of water-soluble liquid additive FraC34, composed of butyric and propionic acid monogly cerides, was evaluated in Hy-line laying hens. Result The results showed that:(1)With oral inoculation of 3×109CFU bacteria per chicken, the morbidity was 100% for 12-days old Hy-line laying hens, but no disease detected for 22-days old ones with oral inoculation of 3×109 or 6×109CFU bacteria per chicken. When the 12-days old chicken were inoculated subcutaneously with 0.4×109CFU bacteria per chicken, the rate of the sick was 70%, and 25% for 22-days old ones when inoculated intracheally with 1.5×109 CFU bacteria per chicken. (2)Adding FraC34 in drinking water of laying hens could improve the intestinal tract and reduce the susceptibility to APEC in the early stage. The addition of 2.0-3.0 L·m-3 FraC34 in drinking water could significantly reduce the morbidity and mortality rate for chickens infected with APEC by oral inoculation and mortality rate of which with intratracheal inner wall inoculation.The daily gain of chicken could be maintained when treated by 3.0 L·m-3 FraC34. Conclusion The serotype O78 APEC strain was pathogenic to young chicks and led to serious economic losses, but not susceptible for older chicken.FraC34 had protective effect and could maintain the production performance of the chicken infected with APEC, which could be applied instead of some antibiotics for efficient production of poultry.
2019, 34(2): 214-222.
doi: 10.19303/j.issn.1008-0384.2019.02.012
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Objective The distribution of 6 resistance genes in 40 cultivated rice varieties in Zhejiang (CRZ) and 6 physiological race identification (PRI) cultivars of Magnaporthe grisea as well as the blast resistance of the rice seedlings were studied. Method The distribution of 6 resistance genes, i.e., Pi1, Pi9/Piz, Pi2/Pizt, Pikh, Pikm and Pita, in the rice varieties was obtained using functional markers. The resistance to M. grisea of all 46 rice varieties was determined based on the 141 strains collected in the field from 2015 to 2017. Result Among the resistance genes, Pita had the highest distribution frequency at 47.83% followed by Pikh at 41.30%; Pi2/Pizt and Pikm, same at 34.78%; Pi9/Piz, low at 21.74%; and Pi1 found only in TTP, one of PRI cultivars. In all, there were 22 rice varieties that showed a resistance rate beyond 60%, and 2 varieties more than 80%. Conclusion The resistance genes carried by the 40 CRZ and the 6 PRI cultivars partially correlated with the resistance level exhibited by the cultivars.
2019, 34(2): 223-228.
doi: 10.19303/j.issn.1008-0384.2019.02.013
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Objective To identify the variations on volatile organic compounds (VOCs) in mango leaves due to infestation by Procontarinai robusta for future study to mitigate or control the disease caused by the midge. Method The VOCs in healthy leaves from a mango tree were compared with those in the midge-infested leaves by using headspace solid-phase microextraction (SPME) combined with gas chromatography mass spectrometry (GC–MS). Result The healthy leaves were found to contain 65 VOCs, while the diseased ones 66 VOCs. Between them, 45 were identical which included caryophyllene, α-cyanene, octadecene, decene, hydrocelene, β-Myrcene, and terpenes. In the diseased leaves, 31 terpenes contributed 51.41%, while 13 aromatic compounds made up 41.10%, of the total. Besides naphthalene and azulene compounds, methyl-4-(1-methylethylidene)-cyclohexene comprised 24.32%, α-cubebene 8.92%, 3-carene 2.23%, acetate 3-hexen-1-ol 2.23%, 4-carene 1.06%, limonene 1.04%, and α-caryophyllene 1.46%. The content of esters was much higher in the midge-infested leaves than that of the healthy counterparts, and the composition also differed from each other. Minute amounts of substances, such as octanol, lanthanol, spartanol, epichlorohydrin, long citronellol and coumarins, were detected in the healthy leaves but not in the infested samples. Whereas, aristoloene, farnesene and some special naphthalene and azulene aromatic compounds were found only in the midge-infested leaves. Conclusion The VOCs in mango leaves mainly consist of aromatic components and terpenes, the composition and content of which were obviously changed after Procontarinairobusta damage.
2019, 34(2): 229-234.
doi: 10.19303/j.issn.1008-0384.2019.02.014
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Objective Population density of the typical borer pest, Monochamus alternatus, in the Bursaphelenchus xylophilus forest was investigated to seek effective means for detecting and controlling the difficult-to-manage infestation. Method The vertical distributions of oviposition grooves, invasion (entry) and eclosion (exit) holes of M. alternatus inside the infected tree trunks were obtained by systematic random sampling and tree-by-tree, section-by-section close observation on evidence of infestation on trees at Fengshan National Forest Park in Ganzhou, Jiangxi from 2015 to 2017.The data were analyzed for correlations among them. Result The oviposition tracks left on the trunks by M. monochamus constituted 46.07% of the total in the section half way above ground level on a tree less than 8 m high. For the trees equal or taller than 8 m, 53.687% of the marks were found in the lower part of a trunk. The quantitative distribution of larval invasion and adult eclosion holes on the diseased trees ranked in the order of middle section > lower section > upper section. Of which, approximately 50% were in the middle section of a tree trunk. The total number of oviposition grooves and invasion and eclosion holes correlated with tree height. No oviposition groove was observed on dead tree stumps, and few invasion and eclosion holes were found which amounted to merely 0.54% and 0.29%, respectively, of the total. The number of boreholes (i.e., the combined total of oviposition grooves and invasion and eclosion holes) in the lower part of the trunk significantly correlated with the number of eclosion holes in the entire tree. However, it was more accurate and reliable to estimate the total number of eclosion holes on a tree by using the count of invasion holes in the lower section. Conclusion Using the invasion hole count in lower trunk section to estimate the total number of eclosion holes on a infested tree was considered a convenient, quick and reliable way for studying the M. monochamus infestation in a B. xylophilus forest.
2019, 34(2): 235-240.
doi: 10.19303/j.issn.1008-0384.2019.02.015
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Objective Effect of forage on fecundity of the highly reproductive and widely spread polyphagous pest, Spodoptera litura Fabricius, was studied. Method Under the laboratory conditions, insects were raised individually on different diet or host plant to monitor the effects on the fecundity, vitellogenin (Vg) and vitellogenin receptor (VgR) of adult S. litura. Result No significant differences were observed on the lifespan and response of the pre-oviposition insects as they were fed on a formulated diet, Brassica oleracea, Alternanthera philoxeroides or Ipomoea batatas. On the other hand, the fecundity, Vg and VgR of the adult females differed significantly whether they were on the formulated diet (control) or the host materials. An individual adult female on the formulated diet would produce 889±43.0 eggs; whereas, one on I. batatas laid 496±53.1 eggs; one on A. philoxeroides, 362±37.3 eggs; and, one on B. oleracea, 193±9.7 eggs. The relative Vg and VgR transcript levels of the female moth population fed on the host materials were merely 40% to 80% of those of control. And, those measurements correlated well with the fecundity of the insect. Conclusion After feeding on various hosts, the titers of Vg and VgR of S. litura differed in comparison to control diet which directly affected the egg development and fertility of the insect.
2019, 34(2): 241-246.
doi: 10.19303/j.issn.1008-0384.2019.02.016
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Objective To provide the fundamental scientific information on Azolla for preservation and study the effects of environmental conditions on the growth and ecological stoichiometry of the aquatic plants in the ecosystem. Method Using a soil water culture under a net cover (SWN) or a nutrient water culture in a greenhouse (NWG), the biomasses and ecological stoichiometric characteristics on C, N and P of 8 varieties of Azolla, including A. filiculoides lamarck, A. Mexicana Schlecht et cham, A. caroliniana Willd, A. microphylla Kaulf, A. imbricate (Roxb.) Nakais, A. pinnata R. Brown, A. microphylla Kaulf and A. microphylla Minyu No.1, were compared. Result In SWN, the biomasses and contents of C and N of all 8 varieties were higher than those in NWG, but the P contents were lower. The C:P and N:P ratios of the plants in SWN were higher than those in NWG, whereas, the C:N ratios were similar. Since the N:P ratios of all plants grown in either SWN or NMG were below 14, N was presumably the primary factor affecting the plant growth. Conclusion Cultivation in SWN appeared to be more conducive than NWG to the growth of Azolla plants. In addition, N seemed to be a crucial nutrient, more so than C or P, for the growth of Azolla.
2019, 34(2): 247-254.
doi: 10.19303/j.issn.1008-0384.2019.02.017
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Objective Heavy metal accumulations in organs of crawfish at Caohai Lake in Guizhou were measured to determine the effect of environmental pollution, providing reference for the healthy cultivation of crayfish and scientific evaluation on the heavy metal contamination. Method Samples of water, sediment and crayfish were collected from various locations on the lake for heavy metal determination. An experiment of live crayfish cultivated under enriched Cu2+ and Cd2+ conditions was conducted in the laboratory to generate a simulated heavy metal transfer model. The contents of Cu, Cd, Pb, Zn and Hg in the collected soil and crayfish samples as well as in the various organs of the cultivated crayfish were determined by atomic absorption spectrometry. Pearson correlation analysis and variance analysis were applied to analyze the data. Result All 5 heavy metals were detected in the crayfish, sediment and water samples from the lake. The metal contents in the crayfish organs differed in the order of viscera > shell > meat. The Pearson correlation analysis showed that Cd, Pb and Zn in the sampled crayfish significantly correlated with those in the sampled sediment, but not the water samples.The heavy metal concentration in the viscera, but not in the shell, meat or claw, of the crayfish raised in the lab increased with increasing heavy metal addition to the water. Conclusion The contamination of heavy metals in crayfish closely related to the conditions of the lake in which it lived. And, the heavy metal contents varied in different organs of the shellfish.