Journal of Northwest A&F University 

About: Journal of Northwest A&F University is an academic journal. The journal publishes majorly in the area(s): Rural area & China. Over the lifetime, 547 publications have been published receiving 931 citations.

Study on the effect of actinomycetes on microflora of replanted strawberry's root domain and the bio-control effectiveness.

Abstract: 【Objective】 The study explored the effects of bio-control and growth promoting after actinomycetes Act11 and Act12 were inoculated,meanwhile investigated the population of microbe in the root domain of strawberry.【Method】 Plot tests in unprotected field were carried out to reveal bio-control effects and growth influence,the dilution-plate culture was used to show the population of microbe in the root domain of strawberry.【Result】 ①The results indicated that,when Act11 and Act12 were inoculated,the population of microbe was obviously affected,the gross amount of bacteria and actinomycetes in root surface increased by 71.4%-100.0% and 112.9%-234.9% respectively compared to control treatment,meanwhile the gross amount of fungi and actinomycetes in roots increased by 70.3%-71.8% and 78.6%-90.2% separately.The ratio of the actinomycetes/bacteria,atinomycetes/fungi,bacteria /fungi at root zone,root surface,roots also increased when Act11 and Act12 were inoculated,actinomycetes/bacteria in root zone,root surface,roots was 1.63 times,1.67 times and 8.8 times more than control treatment separately,atinomycetes/fungi in root surface and roots increased 3.2 times and 3.3 times respectively.②Act11 and Act12 could colonize in strawberry's root and the soil surroundings,the colonization density of Act11 and Act12 in the root surface was 1.30×107 cfu/g and 5.76×107 cfu/g respectively,colonization ratio was 32.3% and 92.4%.③Plot test showed that Act11 and Act12 had good promoting effects on the growth of the bio-mass of strawberry.The new fibre biomass was increased by 31.3% and 112.5% respectively,and the number of stolon was increased by 109.4% and 168.8% separately.④Act11 and Act12 could obviously control replant disease of strawberry,the relative efficiency in unprotected was 28.6% and 84.7% respectively.【Conclusion】 It shows that Act11 and Act12 could ameliorate the micro-ecosystem of the root domain,enhance the disease resistance and improve the biomass of strawberry.

Bioactivity of cantharidin against eleven pests

Abstract: 【Objective】The study was done in order to ascertain the further insecticidal spectra and mode of action of the natural product,cantharidin.【Method】Bioactivity of cantharidin was tested against eleven pests by different laboratory bioassay methods,and the toxic symptom of adult housefly was observed.【Result】Cantharidin had certain stomach action against housefly adults,but it had no contact or fumiganting action.Its LC50 values of stomach toxicity to the housefly adults were 781.90mg/L(48h)and 397.23mg/L(72h),and the stomach toxicity of cantharidin on adult housefly was slow,because the housefly did not show toxic symptom until 18hafter treatment.Its LC50value of stomach toxicity and LD50value of contact toxicity against adult corn weevils after 48hwere 373.17mg/L and 0.36μg/insect,respectively.Its LD50values of contact toxicity against fourtn-instar larvea of Pryeria sinica M were 0.084μg/insect(24h)and 0.049μg/insect(48h).The LC50 values for contact toxicity of 1.0% cantharidin EC to Myzus persicae,Macrosiphoniella sanborni,Hyaloptera amygdali,Lipaphis erysimi and Macrosiphum roswomm after 12h were 19.52,15.84,16.63,25.94and 26.20mg/L,respectively.The LC50 values for contact toxicity of 1.0% cantharidin EC to Tetranychus cinnabarinus,Penthaleus major and Tetranychus viennensis after 12h were 8.26,13.38 and 8.46mg/L,respectively.【Conclusion】It is clear from the mentioned facts above that the cantharidin has insecticidal effect on different kinds of pests to different degrees,and its main mode of action is contact as well as stomach toxicity.

Cloning and sequence analysis of a new dehydrin gene (WZY2) from wheat.

Abstract: 【Objective】The objective of this study was to isolate and clone the dehydrin gene from Zhengyin No.1.【Method】Using the method of RACE,with PEG stress wheat seedlings,dehydrin gene from Zhengyin No.1 was cloned and the sequence was analyzed by bioinformatics software.【Result】A full-length sequence of a new dehydrin gene was amplified;the gene has a length of 849 bp,including a 459 bp ORF(open reading frame).Analysis shows that the protein sequence of the gene encoded has the characteristics of dehydrin genes:the K fragment,S and Y fragment.It is a YSK2 dehydrin formed by two K fragments,a S and a Y fragment.The high hydrophilicity of the protein indicates that it plays an important role in binding the free water and stabilizing the membrane.【Conclusion】The dehydrin gene WZY2 cloned from Zhengyin No.1 provides further information on the structure of dehydrin and it has possible function in plant tolerance to drought.

Induction of autotetraploid of Paulownia australis and its in vitro plantlet regeneration

Abstract: 【Objective】 Induction of Paulownia australis autotetroploid with colchicines was investigated and the system of in vitro plantlet regeneration with different explants was established in order to lay foundation for the breeding of new variant of Paulownia plants.【Method】 The diploidy leaves on the liquid-solid double layer MS media with different colchicines concentrations were used to induce the autotetraploid and the ploidy levels were analysed through chromosome numbering of the plant root tip cells and DNA relative content of the leaf single cell.【Result】 The concentrations of colchicine and the treatment periods were significantly different,and pre-culture time was not significantly different to the autotetraploidy induction.The highest induction rate might reach 18.8% from non pre-cultured leaves treated with 10 mg/L colchicine for 72 h on the MS medium.Leaves of the autotetraploids were larger and thicker,and the stomatal size and density on the leaf larger and thinner than those of the diploid,and the chlorophyll content and SOD activities of the autotetraploids became higher and MDA content and POD activity lower than those of the diploids.MS+0.1 mg/L NAA+8 mg/L BA,MS+0.3 mg/L NAA+12 mg/L BA and 1/2 MS were the optimal media for shoot and root induction respectively.【Conclusion】 The autotetroploid of Paulownia australis was induced and the system of its in vitro plantlet regeneration was established.Moreover,leaves were the suitable explants for the in vitro plantlet regeneration.