Co-reporter:Qiu-Yan SongHai-Tao Yu, Xing-Xu Zhang, Zhi-Biao Nan, Kun Gao
Organic Letters 2017 Volume 19(Issue 1) pp:298-300
Publication Date(Web):December 28, 2016
DOI:10.1021/acs.orglett.6b03568
One novel hybrid peptide–polyketide, dahurelmusin A (1), was isolated from Elymus dahuricus infected by the Epichloë bromicola endophyte. Comprehensive spectroscopic analysis revealed that 1 is the first example of hybrid peptide–polyketide possessing an unprecedented 5-hydroxy-2,2,4,6-tetramethyl-3-oxooctanoic acid moiety. The single-crystal X-ray diffraction analyses allowed the absolute configuration assignment of this compound. Compound 1 also exhibited significant insecticidal activities against Rhopalosiphum padi and Brevicoryne brassicae with LC50 values of 0.092 and 0.251 mM, respectively.
Co-reporter:Tao Chen;Michael Christensen;Fujiang Hou
Plant and Soil 2017 Volume 413( Issue 1-2) pp:303-317
Publication Date(Web):10 November 2016
DOI:10.1007/s11104-016-3103-y
Plant–soil feedbacks (PSFs) and grazing drive community dynamics in grasslands. We examined how the intensity of grazing and PSF interact to affect plant growth and explored what drives the observed feedback effects.Three dominant perennial plant species; Artemisia capillaris, Lespedeza davurica, and Stipa bungeana were grown in field-conditioned soil (sterilized or unsterilized) collected from four grazing intensities in a semiarid grassland of northwest China. Soil nutrient concentrations and root fungal communities were determined.Plant biomass increased with grazing intensity for the three plant species. Within each grazing intensity, plant growth in sterilized soil relative to unsterilized soil differed markedly among species. Soil inorganic nitrogen (N) concentration tended to increase with increasing grazing intensity. Arbuscular mycorrhizal fungi (AMF) colonization was high for all grazing intensities for L. davurica. Fusarium tricinctum, the most common pathogenic Fusarium species, had the highest frequency from the control for A. capillaris and tended to increase with increasing grazing intensity for S. bungeana.Our results suggest that in grasslands plant growth can be modified by the intensity of grazing via grazing-induced changes in soil nutrient availability and fungal communities. Additional studies are needed to determine how grazing intensity affects species co-existence through PSFs to mixed communities.
Co-reporter:Xueli Niu
Water, Air, & Soil Pollution 2017 Volume 228( Issue 3) pp:
Publication Date(Web):2017 March
DOI:10.1007/s11270-017-3289-5
Native grasses that have acceptable forage yield and quality can play an important role in the sustainable development and protection of soil ecosystem. In this study, we investigate a native grass of northern China, Cleistogenes songorica, showing promise for erosion control. We used a rainfall simulation method to compare the effects of C. songorica roots and tall fescue roots (Festuca arundinacea) on soil erosion in sandy loam field plots with irrigation during establishment in 2011 and under mild or severe drought treatments in 2012 and 2013. Root length (RL), root diameter (RD), soil bulk density (SBD), soil field capacity (FC), sediment yield (SY), and root biomass (RB) of each soil monolith were sampled in the topsoil layer (0–10 cm) with a rectangular geotome. The proportion of stable aggregates in soil and the soil anti-scouring properties were also evaluated. C. songorica had higher RD than tall fescue throughout the experiment and evolved higher RL and RB by 2013. Both C. songorica and tall fescue enhanced the erosion resistance of soil, but C. songorica stabilized soil more effectively than did tall fescue. The proportion of stable soil aggregates was greater in C. songorica plots than in tall fescue grassland under mild drought. The present study shows that C. songorica has great potential to be one of the biological resources for soil erosion resistance, water and soil conservation in arid and semi-arid areas.
Co-reporter:Tao Chen, Michael Christensen, Zhibiao Nan, Fujiang Hou
Journal of Arid Environments 2017 Volume 144(Volume 144) pp:
Publication Date(Web):1 September 2017
DOI:10.1016/j.jaridenv.2017.04.006
•Seed size showed a hump-shaped trend with increasing grazing intensity.•The size of seed was decreased greatly by the intensity of 8.7 sheep/ha.•Germination characteristics of seed from plants were enhanced by the intensity of 8.7 sheep/ha.•The occurrence of pathogenic Fusarium species on seeds decreased with grazing intensity.Lespedeza davurica, a major semi-shrub leguminous plant of the vast semi-arid grasslands in northwest China, has decreased greatly in abundance due to overgrazing. Seed characteristics and fungal pathogens affect seedling recruitment from soil seed banks. However, little is known about how grazing affects seed characteristics and fungal colonization on seeds. Seeds of L. davurica were obtained both from plants and from soil from plots where four intensities of grazing (0, 2.7, 5.3 and 8.7 sheep/ha) had been applied for 13 years. The morphological and germination characteristics and colonization of seed by fungi were examined. Seed size showed a hump-shaped trend with increasing grazing intensity. With freshly harvested seed, the intensity of 8.7 sheep/ha significantly enhanced germination and extended the time over which germination occurred. The occurrence of pathogenic Fusarium species on seeds decreased with increasing grazing intensity. Our study strongly suggests that the intensity of grazing can alter seed morphological and germination characteristics, as well as the colonization of fungi on seeds. Additional studies involving more members of the plant community are needed to determine whether the intensity of grazing results in a compensatory mechanism that serves to enhance the possibility of plant recruitment from seeds under field conditions.
Co-reporter:Qiu-Yan Song, Zhi-Biao Nan, Kun Gao, Hui Song, Pei Tian, Xing-Xu Zhang, Chun-Jie Li, Wen-Bo Xu, and Xiu-Zhang Li
Journal of Agricultural and Food Chemistry 2015 Volume 63(Issue 40) pp:8787-8792
Publication Date(Web):September 22, 2015
DOI:10.1021/acs.jafc.5b04260
The development of high-quality herbage is an important aspect of animal husbandry. Inoculating beneficial fungi onto inferior grass is a feasible strategy for producing new varieties of high-quality herbage. Epichloë bromicola is a candidate fungus that is isolated from Elymus tangutorum. A total of 17 metabolites, 1–17, were obtained from E. bromicola, and their biological activities were assayed. Metabolite 1 exhibited antifungal activities against Alternaria alternata, Fusarium avenaceum, Bipolaris sorokiniana, and Curvularia lunata. EC50 values ranged from 0.7 to 5.3 μM, which were better than the positive control, chlorothalonil. Metabolite 8 displayed obvious phytotoxic effects toward Lolium perenne and Poa crymophila seedlings, and it was as active as glyphosate. None of these isolated metabolites displayed cytotoxicity against Madin-Darby bovine kidney cells. The IC50 values were greater than 100 μM, and the metabolites increased the growth of the cells at a concentration of 12.5 μM. The bioassay indicated that E. bromicola may be a beneficial fungus for producing new varieties of herbage with various resistances. Additionally, metabolite 7, 3-(2′-(4″-hydroxyphenyl)acetoxy)-2S-methylpropanoic acid, is a new natural product, and its stereochemistry was determined by means of optical rotation computation and chemical reactions.
Co-reporter:XingXu Zhang;Chao Xia;ChunJie Li
Science China Life Sciences 2015 Volume 58( Issue 5) pp:512-514
Publication Date(Web):2015 May
DOI:10.1007/s11427-015-4837-0
Co-reporter:Minzhi Ma;Michael J. Christensen
European Journal of Plant Pathology 2015 Volume 141( Issue 3) pp:571-583
Publication Date(Web):2015 March
DOI:10.1007/s10658-014-0563-x
To determine whether infection by a fungal endophyte of the genus Epichloë has a modifying influence on pathogenic fungal stress, endophyte-infected (E+) and endophyte-free (E-) seeds of perennial ryegrass (Lolium perenne), inoculated with the ryegrass pathogens Alternaria alternata, Ascochyta leptospora, Bipolaris sorokiniana, Curvularia lunata and Fusarium avenaceum were used for germination experiments and quantification of oxidative stress. Four measures of oxidative stress were used: malonaldehyde (MDA) content, peroxidases (POD) and superoxide dismutase (SOD) activity, and proline content. MDA content, an indicator of membrane lipid peroxidation damage, was significantly lower in E+ seedlings than in E- seedlings under stress from the test fungi. POD activity of E+ seedlings exposed to A. alternata, B. sorokiniana and C. lunata was significantly higher than similarly challenged E- seedlings. SOD activity of E+ seedlings was significantly higher than E- seedlings after exposure to A. alternata, B. sorokiniana, C. lunata and As. leptospora. Proline content of E+ seedlings exposed to the five pathogens was significantly higher than E- seedlings. Interestingly, these effects were present in the absence of disease symptoms apart from some root browning of E+ and E- seedlings exposed to B. sorokiniana. The results of this study showed that the seed-borne endophyte E. festucae var. lolii has potential to enhance establishment of perennial ryegrass by providing protection against pathogenic fungi during the critical early stages of seed germination and subsequent growth.
Co-reporter:Xingxu Zhang, Zhibiao Nan, Chunjie Li, and Kun Gao
Journal of Agricultural and Food Chemistry 2014 Volume 62(Issue 30) pp:7419-7422
Publication Date(Web):May 22, 2014
DOI:10.1021/jf502264j
Ergonovine or ergonovinine was isolated from the aerial parts of endophyte (Neotyphodium gansuense) infected (E+) drunken horse grass (Achnatherum inebrians), neither of which existed in endophyte-free (E−) plants. Both of these ergot alkaloids had a cytotoxic effect on animal smooth muscle cells and increased cell growth inhibition with greater concentrations, in a significantly (P < 0.05) positive correlation. The median inhibitory concentrations (IC50) for ergonovine and ergonovinine were 71.95 and 72.75 μg/mL, respectively. These results indicate that endophytic ergot alkaloids may be the cause of drunken horse grass poisoning.
Co-reporter:XingXu Zhang;YanPei Wu
Science China Life Sciences 2014 Volume 57( Issue 12) pp:1234-1235
Publication Date(Web):2014 December
DOI:10.1007/s11427-014-4660-z
Co-reporter:Hui Song
Science Bulletin 2014 Volume 59( Issue 11) pp:1129-1138
Publication Date(Web):2014 April
DOI:10.1007/s11434-014-0155-3
The class of nucleotide-binding site (NBS)-Leucine-rich repeat (LRR) disease resistance genes play an important role in defending plants from a variety of pathogens and insect pests. Consequently, many NBS-LRR genes have been identified in various plant species. In this study, we identified 617 NBS-encoding genes in the Medicago truncatula genome (Mt3.5v5) and divided them into two groups, regular (490) and non-regular (127) NBS-LRR genes. The regular NBS-LRR genes were characterized on the bases of structural diversity, chromosomal location, gene duplication, conserved protein motifs, and EST expression profiling. According to N-terminal motifs and LRR motifs, the 490 regular NBS-LRR genes were then classified into 10 types: CC-NBS (4), CC-NBS-LRR (212), TIR-NBS (20), TIR-NBS-LRR (160), TIR-NBS-TIR (1), TIR-NBS-TIR-LRR (2), NBS-TIR (7), NBS-TIR-LRR (1), NBS (10), and NBS-LRR (73). Analysis of the physical location and duplications of the regular NBS-LRR genes revealed that the M. truncatula genome is similar to rice. Interestingly, we found that TIR-type genes are more frequently expressed than non-TIR-type genes in M. truncatula, whereas the number of non-TIR-type regular NBS-LRR genes was greater than TIR-type genes, suggesting the gene expression was not associated with the total number of NBS-LRR genes. Moreover, we found that the phylogenetic tree supported our division of the regular NBS-LRR genes into two distinct clades (TIR-type and non-TIR-type), but some of the non-TIR-type lineages contain TIR-type genes. These analyses provide a robust database of NBS-LRR genes in M. truncatula that will facilitate the isolation of new resistance genes and breeding strategies to engineer disease resistance in leguminous crop.
Co-reporter:Zhenfen Zhang
European Journal of Plant Pathology 2014 Volume 139( Issue 2) pp:349-358
Publication Date(Web):2014 June
DOI:10.1007/s10658-014-0390-0
Erwinia persicina (Ep) is a phytopathogenic bacteria found on Medicago sativa, Glycine max, Phaseolus vulgaris and Pisum sativum. It has also been isolated from healthy tomato, cucumber, banana, apple and pear, as well as the human urinary tract and biofilms located on paleolithic rock paintings. The host range and environmental adaptation capacity of Ep, and its life cycle on the lucerne plant, was studied. It was found that an Ep infection, which could be transmitted by seeds, water, and soil, caused necrosis and wilting of the whole mature lucerne plant. Subsequently, 15 genera and 22 species of forage or grain legumes were chosen to determine the pathogenicity of Ep. Among them were 11 genera and 19 species (e.g., Vigna angularis, Arachis hypogaea, Onobrychis viciaefolia, Astragalus adsurgens, etc.) reported as new hosts. The environmental adaptation capacity of Ep indicated its probable survival within a wide range of environmental conditions and an ability to endure arid, saline and alkaline environments. Based on the results of the life cycle, host range and environmental adaptation capacity of Ep, it was concluded that Ep could pose a new threat to forage or grain legumes production within farming systems.
Co-reporter:Zhenfen Zhang
European Journal of Plant Pathology 2013 Volume 135( Issue 1) pp:5-9
Publication Date(Web):2013 January
DOI:10.1007/s10658-012-0072-8
A previously unreported sprout decay disease of lucerne affecting as many as 15 % of sprouts was observed in Northwest China (Gansu province) in May of 2011. Bacteria were isolated and a range of identification methods undertaken including bacteriological tests, carbon source utilization profiling (Biolog) and 16S rDNA sequence analysis. The bacterial isolates (YZ-DS 1, 2, and 3) were finally identified as Enterobacter cloacae. Lucerne seed inoculations revealed that E. cloacae isolated from infected sprouts produced a yellowing and rot similar to that observed on the original symptomatic sprouts, thus identifying E. cloacae as the causal agent of the outbreak. To our knowledge, this is first report of E. cloacae causing sprout decay of lucerne worldwide.
Co-reporter:Jia Chen, Ya Li, Li-Qiong Yang, Yan-Zhong Li, Zhi-Biao Nan, Kun Gao
Food Chemistry 2012 Volume 131(Issue 2) pp:546-551
Publication Date(Web):15 March 2012
DOI:10.1016/j.foodchem.2011.09.021
The present study was aimed at the identification of biological components from pathogenic-infected Astragalus adsurgens with an activity-guided purification process. Fifteen flavonoids were obtained from the most active ethyl acetate fraction and identified as astradsurnin (1), a new chalcone derivative, together with fourteen known flavonoids (2–15). These compounds were tested for antibacterial activities against five bacteria and cytotoxic activities against two selected cancer cells. Within the series of flavonoids tested, compounds 4 and 15 were the most active against Escherichia coli, Bacillus cereus, Staphylococcus aureus, Erwinia carotovora and Bacillus subtilis with MICs ranging from 7.8 to 31.3 μg/ml. Moreover, compounds 4 and 5 exhibited moderate activity against HL-60 and SMMC-7721 cells with IC50 values between 5 and 10 μg/ml. To our knowledge, this is the first time that it has been reported on the biological and chemical study of A. adsurgens infected by Embellisia astragali.Highlights► EtOAc extract from infected Astragalus adsurgens showed antibacterial activity. ► Four compounds displayed inhibitory activities against tested bacteria. ► Nine compounds exhibited moderate activities against tested cancer cells. ► Compound 1 was found to be a new chalone derivative.
Co-reporter:Tianzeng Liu;Fujiang Hou
Nutrient Cycling in Agroecosystems 2011 Volume 91( Issue 1) pp:
Publication Date(Web):2011 September
DOI:10.1007/s10705-011-9445-1
Soil nitrogen transformation has been the subject of growing attention in many semi-arid grassland ecosystems. In our study, we employed an intact soil core in situ incubation technique and measured seasonal changes in soil net nitrogen mineralization and nitrification rates. The measurements were taken from the upper 0–10 cm soil layer of a permanent grassland during a growing season in a 8.5-year field experiment on the Loess Plateau, China that had four grazing intensities (0, 2.7, 5.3 and 8.7 sheep ha−1). Our results demonstrate marked seasonal variations in inorganic nitrogen pools, net nitrogen mineralization and net nitrification. The rates of mineralization and nitrification were highest in August and lowest in September. No consistent differences in monthly net nitrogen mineralization and monthly nitrification rates were observed among the different grazing intensities. Sheep grazing stimulated nitrogen transformation, and the most stimulation occurred at a heavy grazing intensity of 8.7 sheep ha−1. The mean soil net nitrification rate was positively correlated with the soil C/N ratio and pH. The mean N mineralization rate was negatively correlated with soil organic carbon, but was positively correlated with the soil C/N ratio. Our study demonstrated net nitrogen mineralization and nitrification rates were strongly linked to grazing intensity, soil temperature and moisture content.
Co-reporter:Yan Zhong Li;Zhi Biao Nan
Antonie van Leeuwenhoek 2009 Volume 95( Issue 3) pp:275-284
Publication Date(Web):2009 March
DOI:10.1007/s10482-009-9310-2
Embellisia astragali is a strong, virulent pathogen that develops within milk vetch (Astragalus adsurgens). In order to determine nutrient requirements, the fungus was cultured on 9 carbon sources, 9 nitrogen sources, and 13 growth media in the dark at 25°C. Growth rates and sporulation capacity were measured after 4 and 12 weeks. All carbon sources supported growth, but only soluble starch, inulin, and dextrose supported sporulation. In general, better growth was obtained on disaccharides and polysaccharides than on monosaccharides. Compared with no growth on NH4+-N and urea, the fungus grew little on all NO3−-N, amino-N, and other organic-N such as peptone. There was no sporulation or very sparse conidia on almost all nitrogen sources with supplied dextrose or soluble starch as sole carbon source. The better growth and sporulation on most of the semidefined media than on defined media indicates that some components in plant or animal material may be vital to the fungus. Sporulation was positively correlated with growth rate in N source experiment at 12 weeks and in growth media experiment at 4 and 12 weeks. The fungus favors grow within agar with growth rate less than 1.18 mm day−1.
Co-reporter:Pei Tian;Chunjie Li
European Journal of Plant Pathology 2008 Volume 122( Issue 4) pp:593-602
Publication Date(Web):2008 December
DOI:10.1007/s10658-008-9329-7
The effect of the endophyte Neotyphodium lolii on susceptibility of perennial ryegrass (Lolium perenne) to ten fungal pathogens in detached leaves was studied. The pathogens were Alternaria alternata, Ascochyta leptospora, Bipolaris sorokiniana, Curvularia lunata, Fusarium acuminatum, F. avenaceum, F. chlamydosporum, F. solani, F. oxysporum, and Gliocladium roseum. In addition, the effect of the endophyte on four pathogens (A. alternata, B. sorokiniana, Curvularia lunata and F. avenaceum) in living plants was studied, and changes in host superoxide dismutase (SOD) or peroxidases (POD) activity were examined. The total lengths of lesions on detached leaves were greater (P < 0.05) on E- plants than on E+ plants except for A. leptospora although differences between E+ and E- were not consistently significant at all sample times (days after inoculation).The numbers of lesions were greater (P < 0.05) and the lesions were larger (P < 0.05) on intact E- plants than on intact E+ plants for all of the four pathogens. SOD enzyme activity was significantly greater (P < 0.05) in E+ plants than in E- plants only for A. alternata, C. lunata, and F. avenaceum. POD enzyme activity was significantly greater (P < 0.05) in E+ plants than in E- plants only for C. lunata, B. sorokiniana and the uninoculated control.
Co-reporter:Y. Z. Li;Z. B. Nan;F. J. Hou
Australasian Plant Pathology 2007 Volume 36( Issue 4) pp:397-402
Publication Date(Web):2007 July
DOI:10.1071/AP07040
The roles of fungal diseases in the decline of standing milk-vetch pastures were investigated in field plot and glasshouse experiments in Gansu Province, China. Experimental plots within 8-, 6-, 4- and 3-year-old stands were used for measurement of plant populations and productivity, and to survey the mycobiota of root, stem and foliage tissues of healthy plants and diseased plants (showing symptoms of yellow stunt and root rot disease). Selected fungal isolates were tested for pathogenicity by inoculating 2-day-old seedlings grown in pots of sterilised soil. Plant mortality increased and plant density and productivity decreased progressively with age of stand. Of the 27 fungal species of 21 genera isolated from field-grown plants, the most frequently isolated from roots were Fusarium chlamydosporum and F. solani (other Fusarium spp. were also common), whereas Embellisia sp. and Alternaria sp. were most common from aerial tissues of diseased plants. The 11 species tested for pathogenicity could be divided into four virulent types: strongly virulent (Embellisia sp.), moderately virulent (F. oxysporum, F. chlamydosporum and F. avenaceum), weakly virulent (F. solani, F. semitectum, F. verticilloides, Conostachys rosea and Cladosporium herbarum) and non-virulent (Alternaria alternata and Alternaria sp.). Root rot caused by Embellisia sp., together with Fusarium spp. and C. rosea, appears to be the main fungal disease contributor to decline of standing milk-vetch pasture in northern China.
Co-reporter:Yan Zhong Li;Zhi Biao Nan
Mycopathologia 2007 Volume 163( Issue 6) pp:327-334
Publication Date(Web):2007 June
DOI:10.1007/s11046-007-9002-2
An Embellisia sp. has been established as the cause of a new disease of the herbaceous perennial forage legume, ‹standing milkvetch’ (Astragalus adsurgens Pall.) in Northern China, which severely reduces plant density and degrades A. adsurgens stands. The disease was common at an experimental location in Gansu Province where it was recognized by the occurrence of stunted plants with reddish-brown stems and yellow and necrotic leaf blades. An Embellisia sp. was isolated from symptomatic stem, leaf blade, petiole, and root tissues at varying frequencies of up to 90%. Single-spore isolates grew very slowly on PCA, PDA, V-8 and, wheat hay decoction agar. Pathogenicity was confirmed by inoculation of seeds, dipping 2-day-old pre-germinated seedlings in inoculum and spraying inoculum on 6-month-old plants. Symptoms on test plants included yellow leaf lesions, brown lesions on stems and petioles, stunted side-shoots with yellow, small, distorted and necrotic leaves, shoot blight, bud death, crown rot, root rot, and plant death. The disease is named as ‹yellow stunt and root rot’ of A. adsurgens to distinguish it from diseases caused by other known pathogens. Embellisia sp. is also pathogenic to A. sinicus but not to 11 other tested plant species.
Co-reporter:Chun-jie LI, Jia-hui GAO, Zhi-biao NAN
Mycological Research (October 2007) Volume 111(Issue 10) pp:1220-1227
Publication Date(Web):1 October 2007
DOI:10.1016/j.mycres.2007.08.012
Interactions of Neotyphodium gansuense, Achnatherum inebrians, and nine fungal pathogens were studied by tests of inhibition of four fungal pathogens by Neotyphodium endophytes in vitro and by inoculation of nine fungal pathogens on detached leaves of endophyte-infected (E+) and endophyte-free (E−) plants. Compared with the controls, most isolates of N. gansuense significantly inhibited the growth in vitro of, in decreasing order of inhibition, Bipolaris sorokiniana, Curvularia lunata, Fusarium acuminatum, and Alternaria alternata. Inhibition zones appeared between pathogens and some isolates of N. gansuense. Some isolates of N. gansuense significantly inhibited sporulation of B. sorokiniana, A. alternata, and C. lunata. However, there was no significant inhibition of F. acuminatum and a few isolates significantly increased sporulation. The leaf inoculation trial indicated that almost all fungal pathogens were able to cause lesions on detached leaves regardless of endophyte status. Both the number and size of disease lesions on E+ A. inebrians leaves caused by A. alternata, F. chlamydosporum, F. oxysporum, and F. solani were reduced compared with those on E− leaves. Only lesion numbers (not size) of Ascochyta leptospora leaf spots were significantly reduced on E+ leaves compared with E− leaves. Conversely, only the length of Ascochyta leptospora leaf spots were significantly smaller on E+ leaves than on E− leaves; numbers of lesions were not significantly affected. C. lunata was strongly pathogenic to both E+ and E− leaves and numerous lesions developed and merged into patches, the leaf surface was covered and the leaf rotted away.
Co-reporter:Zhixin Zhang, Jeremy P.M. Whish, Lindsay W. Bell, Zhibiao Nan
European Journal of Agronomy (March 2017) Volume 84() pp:84-94
Publication Date(Web):1 March 2017
DOI:10.1016/j.eja.2016.12.008
•Dry matter production of forage maize, foxtail millet and Japanese millet decreased with the delay of sowing date, while that of Sudan grass was maximized at a delay of sowing date for two weeks.•Late sowing greatly reduced WUE of forage maize and foxtail millet.•Sowing date has a strong influence on crude protein content for Sudan grass and Japanese millet, but no effect on that of forage maize and foxtail millet.•Annual warm-season forages have potential to provide more options for forage production in rain-fed farming systems in semi-arid environments.Increasing demand for livestock products is driving development of livestock systems worldwide. That requires improved and new forage production options. The Loess Plateau region in central-northern China is an important area for livestock production, as it supports11% and 19% of the country’s cattle and sheep, respectively (China statistical yearbook 2014). The rain-fed semi-arid environment of the Loess Plateau means that maximizing the water-use-efficiency (WUE) of forage production is vital to guarantee enough fodder supply the livestock demand. A three-year field experiment in north-west Loess Plateau compared forage production, water use and water-use-efficiency as well as crude protein (CP) content of forage maize, Sudan grass, foxtail millet and Japanese millet sown at three sowing dates according to the opening rain during 2011–2013. On average, forage maize produced the highest biomass (12.1 t ha−1) and had the highest WUE (43.4 kg DM ha−1 mm−1). This was followed by Sudan grass (7.8 t ha−1; 26.5 kg DM ha−1 mm−1), Japanese millet (6.7 t ha−1; 26.2 kg DM ha−1 mm−1) and foxtail millet (6.7 t ha−1; 24.6 kg DM ha−1 mm−1). Optimizing sowing date played an important role in maximizing forage production and WUE of all tested forages. Compared to the earliest sowing date, a delay of two weeks reduced forage production by 17% in maize, 35% in foxtail millet, and 16% in Japanese millet. A delay of four to six weeks reduced biomass yield by 58% in maize, 57% in foxtail millet, and 56% in Japanese millet. Late sowing also greatly reduced WUE of forage maize and foxtail millet by 33% and 42%, respectively, when compared to early sowing. The middle sowing date maximized forage production and WUE of Sudan grass in two of the three growing seasons, which was 20% and 38% higher than the early and late sowing, respectively. Late sowing in all forages reduced crop water use by 42–57 mm compared to the early sowing. Among four test crops, CP of Sudan grass (7.9%) and forage maize (7.7%) was higher than foxtail millet (6.8%) and Japanese millet (6.7%). Compared with early sowing, CPf in late sowing significantly increased in Sudan grass and decreased in Japanese millet, in contrast, no evident sowing date effect was found in forage maize and foxtail millet. This study showed that all four warm-season annual grasses had high forage production potential, forage maize was the most reliable and efficient option. Forage maize and the millets could easily be integrated into existing cropping systems and provide opportunities as both grain and forage-producing crop to provide added flexibility for farmers.
Co-reporter:Tingyu Duan, Evelina Facelli, Sally E. Smith, F. Andrew Smith, Zhibiao Nan
Soil Biology and Biochemistry (March 2011) Volume 43(Issue 3) pp:571-578
Publication Date(Web):1 March 2011
DOI:10.1016/j.soilbio.2010.11.024
The effects of soil disturbance and residue retention on the functionality of the symbiosis between medic (Medicago truncatula L.) and arbuscular mycorrhizal fungi (AMF) were assessed in a two-stage experiment simulating a crop rotation of wheat (Triticum aestivum L.) followed by medic. Plants were inoculated or not with the AMF, Glomus intraradices and Gigaspora margarita, separately or together. The contribution of the arbuscular mycorrhizal (AM) pathway for P uptake was determined using 32P-labeled soil in a small hyphal compartment accessible only to hyphae of AMF. In general AM colonization was not affected by soil disturbance or residue application and disturbance did not affect hyphal length densities (HLDs) in soil. At 4 weeks disturbance had a negative effect on growth and phosphorus (P) uptake of plants inoculated with G. margarita, but not G. intraradices. By 7 weeks disturbance reduced growth of plants inoculated with G. margarita or AMF mix and total P uptake in all inoculated plants. With the exception of plants inoculated with G. margarita in disturbed soil at 4 weeks, the AM pathway made a significant contribution to P uptake in all AM plants at both harvests. Inoculation with both AMF together eliminated the negative effects of disturbance on AM P uptake and growth, showing that a fungus insensitive to disturbance can compensate for loss of contribution of a sensitive one. Application of residue increased growth and total P uptake of plants but decreased 32P in plants inoculated with the AMF mix in disturbed soil, compared with plants receiving no residue. The AMF responded differently to disturbance and G. intraradices, which was insensitive to disturbance, compensated for lack of contribution by the sensitive G. margarita when they were inoculated together. Colonization of roots and HLDs in soil were not good predictors of the outcomes of AM symbioses on plant growth, P uptake or P delivery via the AM pathway.Research highlights► Soil disturbance did not affect AM colonization of medic or hyphal lengths in soil. ► AM P uptake contributed significantly to total P in all undisturbed treatments. ► Disturbance reduced P delivery via G. margarita, but not via G. intraradices. ► Inoculation with both AM fungi together eliminated negative effects of disturbance. ► Percent colonization was not a good predictor of symbiotic outcomes.
Co-reporter:Ying-Wen Yu, Z.B. Nan, C. Matthew
Agriculture, Ecosystems & Environment (March 2008) Volume 124(Issues 1–2) pp:40-50
Publication Date(Web):March 2008
DOI:10.1016/j.agee.2007.08.010
Co-reporter:Yali Yin, Z.B. Nan, Chunjie Li, Fujiang Hou
Agriculture, Ecosystems & Environment (March 2008) Volume 124(Issues 1–2) pp:51-59
Publication Date(Web):March 2008
DOI:10.1016/j.agee.2007.08.011
Co-reporter:Yubing Fan, Chenggang Wang, Zhibiao Nan
Agricultural Water Management (December 2014) Volume 146() pp:335-345
Publication Date(Web):December 2014
DOI:10.1016/j.agwat.2014.09.001
Co-reporter:Jiyu Zhang, Ulrik P. John, Yanrong Wang, Xi Li, Dilini Gunawardana, Renata M. Polotnianka, German C. Spangenberg, Zhibiao Nan
Journal of Plant Physiology (15 October 2011) Volume 168(Issue 15) pp:1844-1851
Publication Date(Web):15 October 2011
DOI:10.1016/j.jplph.2011.04.005
Cleistogenes songorica is an important perennial grass found in the pastoral steppe of Inner Mongolia. C. songorica flourishes in drought prone environments, and therefore provides an ideal candidate plant system for the identification of drought-tolerance conferring genes. We constructed cDNA libraries from leaves and roots of drought-stressed C. songorica seedlings. Expressed sequence tag (EST) sequencing of 5664 random cDNA clones produced 3579 high quality, trimmed sequences. The average read length of trimmed ESTs was 613 bp. Clustering and assembly identified a non-redundant set of 1499 contigs, including 805 singleton unigenes and 694 multi-member unigenes. The resulting unigenes were functionally categorized according to the Gene Ontology (GO) hierarchy using the in house Bioinformatic Advanced Scientific Computing (BASC) annotation pipeline. Among the total 2.2 Mbp of EST sequence data, 161 putative SSRs were found, a frequency similar to that previously observed in oat and Arabidopsis ESTs. Sixty-three unigenes were functionally annotated as being stress responsive, of which 22 were similar to genes implicated in drought stress response. Using quantitative real time RT-PCR, transcripts of 13 of these 22 genes were shown to be at least three fold more, or less abundant in drought-stressed leaves or roots, with 8 increased and 5 decreased in relative transcript abundance. The C. songorica EST and cDNA collections generated in this study are a valuable resource for microarray-based expression profiling, and functional genomics in order to elucidate their role, and to understand the underlying mechanisms of drought-tolerance in C. songorica.Highlights► Our findings illustrate the potential for targeted functional genomic studies in non-model, non-crop plant species, particularly in extremophiles, to identify novel or enhanced stress tolerance mechanisms. ► A gene discovery and transcript abundance profiling study has been undertaken in Cleistogenes songorica, a grass that thrives in severely water depleted environments in Inner Mongolia. ► Amongst an EST collection from drought stressed plants are many sequences with roles in response to drought stress. ► Transcript abundance profiling revealed that the majority of genes tested were regulated by drought. ► These findings offer a functional insight into the molecular mechanisms used by C. songorica to cope with moisture limitation, and identify potential resources for conferring drought tolerance in sensitive plants.