2020 Vol. 35, No. 11
Display Method:
2020, 35(11): 1171-1178.
doi: 10.19303/j.issn.1008-0384.2020.11.001
Abstract:
Objective To fully exploit and utilize precious purple-black rice resources, strengthen the innovation of special rice resources, expand the planting area of purple-black special rice, and satisfy people's demand for healthy diet. Method A new two-line special rice variety Ziliangyou 737 was cross bred from Zi 392S, a indica glutinous Dual-purpose Genic Male Sterile (DGMS) line with purple-black seed coat developed by Rice Research Institute, Fujian Academy of Agricultural Sciences and Fuhui 737, a self-breeding purple glutinous restorer line in the spring of 2014. The comprehensive trait performances of Ziliangyou 737 were investigated in variety comparative test during 2014-2016 in Fujian, Yunnan, Jiangxi and Anhui. During 2017-2018, it was recommended to join in the regional trial and production trial of the special-purpose purple rice groups independently organized by Yunnan State-owned Capital Operation Jinding Hepu Agricultural Technology Co., Ltd. And during 2018-2019, it was recommended to join in the regional trials of late-cropping special rice groups in Fujian in order to evaluate its comprehensive traits. Result The average yields of Ziliangyou 737 during 2014-2016 in Fujian, Yunnan, Jiangxi, Anhui and other local product comparative tests were more than 7 500.0 kg·hm−2; In the regional trial of special-purpose purple rice group in Yunnan in 2017-2018, the growth period was about 161 days, the plant height was 97.0 cm, the effective panicles were 191, 000 per 667 m2, the ear length was 22.9 cm, the total grains per ear were 179.9, the seed setting rate was 72.1%, 1000-grain weight was 24.9 g, the amylose content was 2.6%, the average yields of the regional trials were 7 564.2 kg·hm−2 and 7 569.3 kg·hm−2 respectively, increased by 148.0% and 156.2% compared to control Guineng purple rice; the average yields of the 2018 production trial was 7 964.7 kg·hm−2, increased by 169.2% compared to control Guineng purple rice; it was approved by the Yunnan Crop Variety Appraisal Committee in 2019 (Dianshendao 2019004). In the regional trials of the late rice special rice group in Fujian Province in 2018 and 2019, the growth period was about 123 days, the effective panicles were 163 000 per 667 m2, the plant height was 108.4 cm, the panicle length was 23.7 cm, and grain number per panicle was 172.4, the seed setting rate was 79.33%, 1 000-grain weight was 24.7 g, amylose content was 2.1%, the regional average yields was 7 475.6 kg/hm2 and 7,535.4 kg/hm2 respectively, decreased by 4.39% and 3.26% compared to control Yiyou 673, it was approved by the Fujian Crop Variety Appraisal Committee in 2020 (Minshendao 20200067). Conclusion Ziliangyou 737 has promising application prospects, with excellent comprehensive agronomic traits, strong heterosis, high yield stability, wide adaptability, deep purple brown rice seed coat, waxy endosperm, excellent rice quality, especially good food taste and other characteristics. It can be promoted as special rice in the hybrid indica rice area below 1 450 meters above sea level in Fujian and Yunnan provinces and other similar ecological regions.
2020, 35(11): 1179-1187.
doi: 10.19303/j.issn.1008-0384.2020.11.002
Abstract:
Objective In search for internal reference genes of Cucumis melo L. that could stably express in different tissues and under stress conditions to warrant accuracy and reliability of the RT-qPCR analysis on target gene expression. Method Expression stabilities of 9 candidate genes, 18srRNA, TUA, EF1a, Actin1, Actin2, Actin3, Actin4, CYC, and UBI-ep, from the roots, leaves, seeds, and fruits of Xinyinhui melon being treated by water, cinnamic acid, saline alkali or ABA were determined by RT-qPCR and analyzed using the BestKeeper, NormFinder, and geNorm software. Result In different tissues, the top 5 choice genes identified by BestKeeper ranked as CYC＞18s rRNA＞UBI-ep＞EF1a＞TUA, those by NormFinder EF1a＞UBIep＞Actin4＞CYC＞Actin3, and those by geNorm Actin4=Actin3＞Actin1＞EF1a＞UBI-ep. Under various stresses, they were 18s rRNA＞Actin3＞Actin4＞EF1a＞UBI-ep as ranked by BestKeeper, EF1a＞UBI-ep＞Actin4＞CYC＞18s rRNA by NormFinder, and EF1a=UBI-ep＞Actin4＞CYC＞Actin by geNorm. Overall, EF1a appeared to be most stable among the 9 genes. Insofar as variety of tissues is concerned, Actin4, Actin3, Actin1, and EF1a were more stable than the others; and, under stress, EF1a and UBI-ep tended to be superior. Conclusion Stably expressed in the tissues under the stresses as tested, EF1a was selected as the reference gene for studies on C. melo to reduce experimental errors. To further ensure accuracy, application of dual reference genes in RT-qPCR analysis might be considered.
2020, 35(11): 1188-1197.
doi: 10.19303/j.issn.1008-0384.2020.11.003
Abstract:
Objective To identify and study the genes in strawberry (Fragaria ananassa) which related to the synthesis of metacaspases (MCs), the enzymes that played vital roles in regulating the programmed cell death (PCD) in plants. Method The physiochemical properties, conserved domains, phylogenetic relationships and conserved motifs of FaMC proteins were analyzed based on strawberry whole genome data. The expressions of FaMC genes in 6 tissues and 6 fruit development stages of strawberry were carried out by qRT-PCR. Result The 21 FaMC proteins identified in this study could be divided into Type-I, Type-I*, and Type-II based on the differences on their sequences. The phylogenetic trees and conserved domains of the 3 different types showed the differentiations between them. Type-I FaMC protein consisted of N-terminal domain (NTD) with one zinc finger motif, Type-I* consisted of NTD but no zinc finger, and Type-II had not NTD. The FaMC genes were distinctively differently expressed in different tissues and developmental stages. Type-I expressed in the leaves, Type-I* in the roots, and Type-II in the flowers. And, during the berry development stage, most Type-I* exhibited a high-low-high U-pattern of changes, whereas, part of Type-I and Type-II had a reversed U-pattern. Conclusion FaMC genes were identified to be closely related to the synthesis of metacaspases that played important roles in the development and growth of strawberry plants.
2020, 35(11): 1198-1206.
doi: 10.19303/j.issn.1008-0384.2020.11.004
Abstract:
Objective Changes on photosynthesis of leaves of muskmelon vines grown by hanging in a greenhouse enriched with CO2 were studied to understand the effect on the plants in a life cycle and application for optimum trellis cultivation. Method Four CO2 enrichment treatments were implemented in the experimentation. They included CK at 400±12 mol·mol−1, T1 at 800±24 mol·mol−1, T2 at 1 200±36 mol·mol−1, and T3 at 1 600±48 mol·mol−1. Changes on the chlorophyll content, photosynthetic indicators, and chlorophyll fluorescence indices of the leaves on the hanging melon vines during the entire growth period were determined in 5, 15, 25, 35, and 45d after the treatments. Result Compared with CK, T2 and T3 increased the net photosynthetic rate by 51.3% and 45.7% and WUE by 58.0% and 114.0%, respectively; while reduced the regulatory energy dissipation quantum yield Y (NPQ) by 7.1% and 11.0%, and the non-photochemical quenching coefficient qN by 5.8% and 6.2%, respectively. For T3, the increase on photochemical quenching coefficient qP was 3.9%. As the leaves aged (i.e., 45-d-old at end of treatment), the net photosynthetic rate under CK was only 19.2% at peak, whereas, that under treatments remained at a higher level. T3 had its net photosynthetic rate increased by 469.2%, chlorophyll A content significantly increased by 20.6%, Y(II) increased by 16.3%, qP increased by 25.1%, and Y(NO) decreased by 13.3% over CK. T1 and T3 showed their stomatal conductance reduced by 35.1% and 31.9%, transpiration rate by 52.8% and 37.7%, and Y(NPQ) by 9.1% and 6.6%, respectively. And, on qN, T1, T2, and T3 decreased by 8.3%, 14.6%, and 1.1%, respectively. Conclusion The photosynthetic capacity of 25-d-old muskmelon leaves reached the maximum with the optimal CO2 enrichment at 1 200 mol·mol−1 under T2. The enrichment in the atmosphere also increased WUE and the photochemical quenching with a reduction on the non-photochemical quenching of the plants. The combined effect would improve the efficiency of leaf photosynthesis during plant senescence when the biochemical process depends on the increased chlorophyll content and qP to function well.
2020, 35(11): 1207-1214.
doi: 10.19303/j.issn.1008-0384.2020.11.005
Abstract:
Objective Effect of grafting on flavoring volatiles in the large-fruit tomatoes was determined to study the flavor regulation of the plant. Method The composition and contents of volatiles in the fruits of the non-grafted (S) and grafted (J) large-fruit varieties, Boshou No. 1, Huiteng, and Huiteng No. 2, were analyzed for comparison using the headspace solid phase micro-extraction with gas chromatography-mass spectrometry. Result There were 59 including 7 unique compounds in the fruits from the Boshou No.1S plants, and 62 with 10 unique compounds in the fruits from the Boshou No.1J plants. On Huiteng S, 59 including 8 unique volatiles, and on Huiteng J, 64 including 13 unique volatiles were identified. For Huiteng No. 2S, 58 including 7 unique compounds were found, while in Huiteng No.2J, 60 including 9 unique compounds were identified. Conclusion The contents of volatile flavoring compounds, 6-methyl-5-hepten-2-one, β-ionone, and E-2-hexenal, were significantly higher in the fruits from the grafted (J) than the non-grafted (S) plants of 3 large-fruit tomato varieties.
2020, 35(11): 1215-1221.
doi: 10.19303/j.issn.1008-0384.2020.11.006
Abstract:
Objective Formulation of culture media was optimized to facilitate the seed germination, tissue propagation, and various developmental stages of Arundina graminifolia. Method An orthogonal experiment was conducted to optimize the media for aseptic germination of the seeds and development of the seedlings of A. graminifolia using 1/2 MS as the base. Application of growth regulators and additives in the solid medium formulation was evaluated in accordance to the seed germination, seedling growth, root development and transplanting efficiency. Result The optimum media for various developmental stages of A. graminifolia were determined to include (1) 1/2 MS + 7 g agar·L−1 + 30.0 g sucrose·L−1 + 1 g activated carbon·L−1 + 100 mL coconut milk·L−1 + 1.0 mg NAA·L−1 + 2.0 mg 6-BA·L−1 + 0.5g Huabao No. 1·L−1 to reach a seed germination rate of 83.79% . (2) 1/2 MS + 7 g agar·L−1 + 3 0g sucrose·L−1 + 1 g activated carbon·L−1 + 1 mg IBA·L−1 + 3 mg 6-BA·L−1 + 0.5 mg NAA·L−1 + 100 g mashed potato·L−1 to achieve an average bud proliferation rate of 1.36. (3) 1/2 MS + 7 g agar·L−1 + 30 g sucrose·L−1 + 1 g activated carbon·L−1 + 0.2 mg IBA·L−1 + 2 mg 6-BA·L−1 + 0.2-0.5 mg NAA·L−1 + 100 g banana puree·L−1 for an optimal root development. (4) Perlite:peat soil mixture at 1 ∶ 1 ratio to yield a seedling survival rate of 98% with desirable transplanting and acclimatization results. Conclusion Coconut milk in culture medium was found to significantly benefit the seed germination. The individually formulated media for various growth stages of A. graminifolia seedlings would help ensure the success in preserving the wild germplasms.
2020, 35(11): 1222-1227.
doi: 10.19303/j.issn.1008-0384.2020.11.007
Abstract:
Objective Effect of exposure to light of varied spectra at night on the cold tolerance of tomato (Lycopersicon esculentum) seedlings was investigated. Method Tomato seedlings grown under supplemental lighting at night by using white (W), red (R) or blue (B) light or combined 2R/8B, 5R/5B or 8R/2B were taken as treatments, and seedlings grown under natural conditions were taken as control. After 20d of cultivation, the plants were subjected to a low-temperature stress of 10/5 ℃ (day/night temperatures) to determine the tolerance of the seedlings toward mild hypothermia. Result The ranges of increased electrolyte permeability and MDA content in the leaves of the treatment seedlings under low-temp stress were significantly lower than those of control. After being exposed at night to the combination of 2R/8B, 5R/5B or 8R/2B, the seedlings could maintain high activities of SOD, CAT, and POD under the low-temp stress. These activities peaked when the 8R/2B was applied to reach significantly 399.49% on SOD, 129.01% on CAT, and 135.74% on POD higher than those of CK, 6d after the seedlings were moved to the low-temp environment. Conclusion Exposing tomato seedlings to light of different spectra at night improved the ability of the plants to tolerate mild hypothermia. The effect was maximized when the seedlings were grown for 20d under the nighttime lighting with 8 red and 2 blue lamps.
2020, 35(11): 1228-1233.
doi: 10.19303/j.issn.1008-0384.2020.11.008
Abstract:
Objective As a genetic marker, the green fluorescent protein gene (gfp) of Fusarium oxysporum f. sp. momodicae (Fom), one of the most serious fungal pathogens that caused the fusarium wilt on bitter gourd, was identified and transformed into bacterium to facilitate the study on the infection process and control of the disease. Method A highly pathogenic wild-type strain, FJAT-3018, isolated from diseased bitter gourds was transformed with the gene encoding gfp using an Agrobacterium-mediated method. The genetically stable transformants, FJAT-31290 and FJAT-31284, were verified by their colony morphology, growth rate, and pathogenicity. Result The efficiency of transforming FJAT-3018 was approximately 14.5 transformants per 106 spores. After 10 generations of subculture, the transformants did not significantly differ from the wild-type strain with respect to the colony morphology, growth rate, and pathogenicity. Strong constitutive expression of gfp could be seen in the fungal hyphae and conidia of the transformants. In addition, under a confocal laser scanning microscope, the transformant-infected bitter gourd plants showed growth of the fungal hyphae inside the roots and stem xylem. Conclusion The gfp gene had been successfully transformed into FJAT-31290 and FJAT-31284 with genetic stability and without apparent pathogenicity deviation from the highly pathogenic wild-type strain FJAT-3018.
2020, 35(11): 1234-1243.
doi: 10.19303/j.issn.1008-0384.2020.11.009
Abstract:
Objective Changes on the key microbial communities in the continuously cropped rhizosphere soil (CCRS) of Achyranthes bidentata Blume were studied to analyze the allelopathic effect for operational improvement on cultivation of the medicinal plants. Method The community structures of Bacillus spp. and Fusarium spp. in the rhizosphere soil of A. bidentata under 1, 10, and 15 years of consecutive monoculture were determined using denaturing gradient gel electrophoresis (DGGE). Soil sample from a virgin land was used as control (CK). Result Abundant Bacillus spp. dominated by B. stubtilis and B. cereus were isolated from the CCRS specimens. The CCRS under 10-year (10Y) and 15-year (15Y) of continuous cropping had a greater relative content of B. subtilis and B. halodurans than their 1-year (1Y) counterpart. With respect to Fusarium spp., the number of bands and species were relatively few, the community structure tended to be similar between CK and 15Y as well as between 1Y and 10Y, and F. solani and F. oxysporum being the dominant species. The qPCR results also indicated that continuous monoculture of A. bidentata increased the abundance of the beneficial bacteria but kept that of the harmful Fusarium spp. largely unchanged. Conclusion Continuous cropping A. bidentata enhanced the diversity and abundance of the beneficial Bacillus spp. without encouraging the expansion of the pathogenic Fusarium community in the rhizosphere. It appeared that the rhizosphere allelopathy under the cultivation practice had created a healthy ecosystem that promoted the growth of A. bidentata.
2020, 35(11): 1244-1251.
doi: 10.19303/j.issn.1008-0384.2020.11.010
Abstract:
Objective Feasibility of using mouse macrophage cell line Raw 264.7 for studies on pathogenesis of Mycoplasma ovipneumoniae(Mo) on sheep was investigated by comparing the proteome changes taken place in both macrophages after an induced Mo infection. Method The primary alveolar macrophages from sheep lung tissue were isolated and used, along with Raw 264.7, for the study. Both macrophages were infected with a standard strain of Mo (MOI=10) for 24h prior to proteomic and RT-PCR analyses to compare the expressions on the target genes in them. Result The image of specific surface antigen CD14 shown on the cells obtained from the lung tissue confirmed the identity of the isolated sheep primary alveolar macrophages. After infected by Mo, both sheep and mouse macrophages showed a similar significant change pattern on the expressions of FADD, IL-1β, NOS2, and THBS1. These proteins are known to associated with the Toll-like receptor signaling pathway, MAPK signaling pathway, and autophagy in biological processes. Conclusion It appeared that Raw 264.7 could be satisfactorily used to substitute the sheep primary alveolar macrophage in a simulated system for studies on Mo pathogenesis to considerably simplify the process and save cost in conducting the experiments on sheep.
2020, 35(11): 1252-1257.
doi: 10.19303/j.issn.1008-0384.2020.11.011
Abstract:
Objective Reproductive performance of Saba sows affected by the animal breed, parity, mating, and farrowing were investigated to explore means for improvements. Method From the 2013-2017 records maintained at Chuxiong Prefecture Pig Breeding Farm in Yunnan province on Saba sows that delivered 182 litters, Duroc×Saba sows (DS) that delivered 67 litters, and Landrace×Saba sows (LS) that delivered 67 litters, the reproductive performances of these sows were compared. The number of parities, insemination methods, and farrowing seasons of the litters by the sows were analyzed using the least square model. Result Compared with the Saba sows, DS and LS had 2.56 and 1.98, respectively, more total number born (TNB) (P＜0.01) and 2.36 and 1.99, respectively, higher number born alive (NBA) (P＜0.01) per litter. In general, the 4th to the 6th parities performed better than the others (P＜0.05 or P＜0.01), and the highest TNB and NBA occurred on the 6th while the lowest on the 1st and 9th parities. No significant differences were found on the performance whether the sows were impregnated by natural service (NS) or artificial insemination (AI) (P＞0.05). However, farrowing in spring and summer rendered more desirable results than in autumn and winter (P＜0.05 or P＜0.01). Conclusion The reproductive performance of Saba sows could be improved by cross-breeding and/or farrowing in spring and summer in a year.
2020, 35(11): 1258-1264.
doi: 10.19303/j.issn.1008-0384.2020.11.012
Abstract:
Objective An in vitro gas production and nutrient degradation test was applied to determine the possibility of using fermented mulberry leaves in feed for Hu sheep. Method Three healthy adult Hu sheep were fed each on alfalfa, Leymus chinensis or fermented mulberry leaves for comparison in this study. Ruminant liquids from the sheep were extracted and designated as ARL (from the sheep fed on alfalfa), LRL (from the sheep fed on L. chinensis), and MRL (from the sheep fed on the fermented mulberry leaves) for the 48 h in vitro simulated fermentation culture test. Production of selected gases and degradation of dry matters and fibers from the test were measured in 48-hour intervals during the fermentation process. Result After 48h of the in vitro fermentation, the total gas produced by MRL was 187.25 mL·g−1, which was significantly higher than LRL (P＜0.01) but not with respect to ARL (P＞0.05); the 46.78 mmol·L−1 total volatile fatty acids (TVFA) significantly higher than either LRL or ARL (P＜0.01); the acetate, propionate, butyrate, valerate, isobutyrate and isovalerate, with the exception of propionate, concentrations of 29.76, 10.18, 4.12, 1.54, 0.48, and 0.70 mmol·L−1, respectively, significantly higher than LRL (P＜0.01); butyrate and valerate significantly higher than ARL (P＜0.01); and, the ratio of
acetate to propionate is 2.92 significantly higher than LRL or ARL (P＜0.01). There were extremely significant differences on NH3-N content among the fermentation broths of MRL, ARL, and LRL at 1.03, 1.75, and 0.71 mmol·mL−1, respectively (P＜0.01). The in vitro dry matter digestibility (IVDMD) by MRL of 46.76% was extremely significantly lower than the others (P＜0.01), but the neutral detergent fiber digestibility (IVNDFD) of 70.25% significantly higher (P＜0.01). Conclusion The in vitro fermentation test with the ruminant liquids employed in this study clearly demonstrated the enhancing effect of MRL in the gas production and nutrient degradation as compared to ARL or LRL. It appeared that the fermented mulberry leaves could be applied in feed to promote the ruminant digestion of Hu sheep.
acetate to propionate is 2.92 significantly higher than LRL or ARL (P＜0.01). There were extremely significant differences on NH3-N content among the fermentation broths of MRL, ARL, and LRL at 1.03, 1.75, and 0.71 mmol·mL−1, respectively (P＜0.01). The in vitro dry matter digestibility (IVDMD) by MRL of 46.76% was extremely significantly lower than the others (P＜0.01), but the neutral detergent fiber digestibility (IVNDFD) of 70.25% significantly higher (P＜0.01).
2020, 35(11): 1265-1270.
doi: 10.19303/j.issn.1008-0384.2020.11.013
Abstract:
Objective Efficient method to amidate the carbon-terminal of the antimicrobial peptide MME through self-splitting intein in recombination fusion proteins expressed in E. coli with DTT in the presences of MESNa and NH4HCO3 was explored. Method Recombinant plasmid of MME was constructed to induce the intein-mediated expression in E. coli to successively obtain fusion proteins composed of histidine, sumo label, target polypeptide, and intein. The proteins were subsequently purified in a process using a nickel column and dialysis. With MESNa and NH4HCO3, an intein self-split procedure was completed by DTT to amidate the carbon-terminal on MME, then cut and purify the intestinal kinase. Both MME and the amidation were verified by the standard mass spectrometry and two-stage, tandem mass spectrometry. Result The resultant gene fragment of the fusion protein was determined by PCR to be 837bp long as expected. In comparison to the theoretical value of 3 057.64, the relative molecular weight of MME obtained by the standard mass spectrometry was 3 057.7. The molecular weight of the amidated carbon-terminal fragments of MME was measured by the two-stage, tandem mass spectrometry to be 1,214.728, which was close to the known theoretical value of 1 214.739 with a matching rate of 45. It appeared that the carbon-terminal of MME had been effectively amidated, and the protein obtained was soluble. Conclusion The recombinant fusion proteins were successfully expressed in E. coli to enable the intein self-splitting in the presences of MESNa and NH4HCO3 and amidate the carbon terminal of MME. Therefore, the current simple, one-step preparation could achieve accurate, duplicatable, and meaningful results. By combining the standard mass spectrometry and two-stage, tandem mass spectrometry, the amidated carbon-terminal polypeptides could satisfactorily be detected.
2020, 35(11): 1271-1279.
doi: 10.19303/j.issn.1008-0384.2020.11.014
Abstract:
Objective Ecotoxicity imposed by nonylphenol (NP) on Eisenia foetida and potential detoxification effect of tea polyphenols were studied. Method Adding different concentrations of tea polyphenols into NP base solution, the relief of tea polyphenols (TP) on the life state, lethal toxicity, avoidance behavior and growth inhibition induced by NP were observed in E. foetida, and the toxic mechanism of NP was studied by HE staining. Result At a concentration in soil ranging between 100-200 mg·kg−1, NP exerted varied degrees of toxicity to the earthworms with lethality directly correlated with the concentration as well as exposure time. The growth of earthworms was retarded by 34% at 200 mg NP·kg−1, and a high mortality rate observed when the concentration reached 400 mg NP·kg−1. The stained tissues of the earthworms under NP stress showed decreased vacuolated gland cells, thinned circular muscles, bared cuticles, and thickened epidermis. Toward the soil with NP in the range of 12.5-200 mg·kg−1, the earthworms displayed a movement avoidance. Upon the addition of tea polyphenols at the concentrations of 70-700 μg·kg−1 in the NP solution, the lethality and growth retardation of the earthworms declined significantly. A tea polyphenols addition of 0.7-7 μg·kg−1 in the NP solution significantly lessened the avoiding response of the earthworms. With 0.7-700 μg·kg−1 of added tea polyphenols, the thickness of the muscular layer of the earthworm body wall increased and the stratum corneum became smooth again. Conclusion NP at a concentration in the range from 100 mg·kg−1 to 400 mg·kg−1 in soil could be toxic or lethal to E. foetida. Whereas, the presence of tea polyphenols at a level between 0.7 μg·kg−1 and 700 μg·kg−1 in the NP solution that was blended in the soil could significantly mitigate the adverse effect induced by NP.
2020, 35(11): 1280-1288.
doi: 10.19303/j.issn.1008-0384.2020.11.015
Abstract:
Objective Effects of underground interactions between roots of maize and soybean plants under intercropping on plant photosynthesis, crop yield, and soil physiochemical properties were investigated to decipher the associated mechanisms. Method A maize/soybean intercropping experimentation was conducted in the field. Underground between the maize and soybean plants, a plastic sheet to completely separate and deprive interactions between the root systems (Q), a nylon mesh to partially block the underground interactions (W) or with no artificial barrier to allow total root-interactions (N) was implemented. SPAD, photosynthetic characteristics, and yield of the plants grown under the varied degrees of partition on the root systems were measured. Result Compared to monoculture, the intercropped maize and soybean under N showed increased chlorophyll contents in the functional leaves by 10.36% and 9.65%, respectively. The net photosynthesis, stomatal conductance, intercellular CO2 concentration, and transpiration rate were also significantly enhanced by the intercropping under varied roots partitions as they ranked N＞W＞Q＞monoculture. The crop yields of the plants were improved by the intercropping under W or N. The land equivalent ratio (LER) of the N treatment was 1.39, while that of W 1.13. Under Q or W, the contents of total and available N, P, and K in rhizosphere soil were higher than those in the monoculture lot. The activities of catalase, acid phosphatase, urease, sucrase, and peroxidase increased in the rhizosphere soil under W or N. A significant correlation was observed between part of the enzyme activity and nutrient content in the soil. Conclusion The interactions between the root systems of the intercropped maize and soybean plants might activate the nutrient pool and enzyme activity in the rhizosphere soil. The leaf chlorophyll of the intercropped plants could also be increased by the underground interactions benefitting the plant photosynthesis with improved crop yield.
