This paper expounded the interaction process between host plant and Fusarium oxysporum from histopathology,physiological biochemical pathology and molecular biology.It also discussed about the relation between Fusarium oxysporum and host plant.
Recent progresses on the research of regeneration system establishment of cucurbit vegetables,methods of transformation and expression of target genes were reviewed in this paper.Problems and prospects of the field of research were also discussed.
The cucumber(Cucumis sativus L.)variety‘Xintaimici’was hydroponically cultured to study the effects of different exogenous concentration Ca(NO3)2 on growth of cucumber seedlings and membrane lipid peroxidation under salt stress(NaCl 65 mmol·L-1).The results showed that exogenousCa(NO3)2 of different concentration could alleviate the growth inhibition,reduce the increasing range of MDA and electrolyte leakage rate caused by salt stress.2.0 mmol·L-1 Ca(NO3)2 is the best treatment.The above soil fresh quality of cucumber seedling,its dry quality,plant height,stem thickness,leaf areas,under ground fresh weight,dry weight,total root length,total root areas,total root size,number of root tips,etc-other growth index were significantly higher than those under single salt stress treatment.At the same time,the MDA content and the increasing electrolyte leakage rate under salt stress were also decreased.
Three cytoplasmic male sterile lines(CMS)and their maintainer lines of the nonheading Chinese cabbage〔Brassica campestris L.ssp.chinensis（L.）Makino var.communis Tsen et Lee〕.were taken as experimental materials,and the contents of chlorophyll,soluble sugar,soluble protein,proline and changes of the activities of SOD,POD,CAT in leaf were tested during seedling.The results showed that the contents of chlorophyll,soluble sugar,soluble protein,proline in CMS were significant lower than their maintainer,while the activities of three protective enzymes(SOD,POD and CAT)were higher in CMS with the treatment of low temperature stress.The contents of chlorophyll and soluble protein decreased continuously in both CMS and their maintainer;while the contents of soluble sugar,praline and the activities of three protective enzymes(SOD,POD and CAT)at first increased,then decreased under cold-stress.There was consistency in all stages of change between CMS and its maintainer line.And after processing,the differences in physiological and biochemical characteristics reduced.All these facts suggested the resistance of cold stress of non-heading Chinese cabbage OguCMS was greatly improved.
Genetic analysis was carried out on P1,P2,F1,F2,BC1P1 and BC1P2 using WI998(gynoecy)and TopMark(andromonoecy)as hybridized combination.Genetic map was constructed by Simple Sequence Repeat Markers(SSR)and melon(Cucumis melo L.)genes determined sex expression were located using F2 generation as materials at the same time.The research indicated that a（andromonoecious）,g（gynomonoecious）and gy（gynoecious）were the three genes which determine sex expression of melon.A genetic map of melon included 31 SSR molecular markers and 2 morphological markers were constructed.Besides,two SSR molecular markers related with sex determination were found.The genetic distances were 13.5 cM between MU55491 marker and gene a and 11.6 cM between MU147232
marker and gene gy，respectively.
The morphological indexes,contents of chlorophyll,soluble protein,soluble sugar and MDA,and activities of several protective enzymes of tomato（Lycopersicon exculentum Mill.）leaf color mutant 06883 treated by different levels of weak light stress were measured in this research.The results show that,under different levels of weak light stress,the decrease value of SLM,VLM,chlorophyll content,activities of protective enzymes and the increase value of plant height/stem diameter,LAR,MDA content of tomato leaf color mutant 06883 are less than that of its wildtype 06884.Therefore,the sensitivity to weak light stress of leaf color mutant 06883 is less than that of its wildtype 06884.It is,to certain extent,tolerant to weak light and could be used as good germplasm resource tolerant to weak light.
Taking broccoli(Brassica oleracea L.var.italica Plenck)variety‘Qingnong 70’and‘Qingnong 80’as experimental materials,this paper studies on plant regeneration factors of microspore embryoids.The results showed that the embryoids age(30-35 days)was optimal to plant regeneration,and the regeneration frequency exceeded 75 %,while it decreased significantly when the embryoids age was over 40 days.The regeneration frequency reached the highest(up to 60 %-70 %)when agar in the medium was 1.2 %.Most of embryoids could not produce plantlets directly,subculture was needed,and this treatment helped to differentiate much more plantlets.The optimal media for subculture was MS+3 % sucrose+1.0 % agar.About half of the regenerated plants were haploid,30 %-35 % plants were double haploid,and the rest were a few tetraploid or chimeras.
Taking clustering ginger（Zingiber officinale Roscoe.）shoot as materials,we compared the doubling effects of its somatic cell chromosome under in vitro cultivation condition and with different colchicines concentration and different treating time period.The results showed that the inducement effect was the best,when shoots were treated in liquid culture medium of 0.2 % colchicines concentration for 8 days.The inducement and survival rate were 42.86 % and 70.00 %,respectively.The chromosome number of tetraploid was 2n=4x=44,while that of the control diploid was 2n=2x=22.Compared with diploid,tetraploid showed characteristics of taller plant height,thicker stem,larger,broader and thicker leaf blade,fewer stomata per unit area,larger stomata,and more chloroplasts in stomata guard cell.The stomata density and chloroplast number in guard cells could be important characteristics distinguishing tetraploid from diploid.
A quantitative determination method for polyphenol content in luffa was studied by using Folin-Ciocalteu colorimetry with gallic acid as standard.The results showed that 2 mL polyphenol contents from luffa could be well calculated according to their colorimetric absorption at 770 nm by applying 2 mL Folin-Ciocalteu reagent,and 4 mL 10 % Na2CO3 for 90 min at 30 ℃ for colorimetric reaction,and the linear range of standard curve was 2-10 mg·L-1.The polyphenol content in luffa could be determined by this method.This method is very stable with good reappearing property and high accuracy.
In this study,the plant morphology of local Chinese cabbage〔Brassica campestris L.ssp.chinensis(L.)Makino varcommunis Tsen et Lee〕‘Jinhua Houdagaojiao’(for short as‘Houdabai’)was observed and its nutritional quality was tested.The results indicated that its moisture content is significantly lower than that of the two control varieties‘Hangzhouyoudonger’and‘Zaoshu No.5’,the crude fiber and total soluble sugar content of‘Houdabai’is higher than that of‘Hangzhouyoudonger’and notably higher than that of‘Zaoshu No.5’.The zinc content of‘Houdabai’is also higher than that of the two control varieties.It was 1.9 times of‘Zaoshu No.5’,and 4.7 times of‘Hangzhouyoudonger’.However,the contents of VC,kalium,phosphor and amino acid were almost the same as‘Hangzhouyoudonger’,but obviously higher than‘Zaoshu No.5’.
In controlled condition of deep flow hydroponics,the experiment studied the effect of iodine on flowering,bearing and yield of cherry tomato(Lycopersicon esculentum var.cerasiforme)treated with solutions of different iodide(I-)concentrations.After I- treatments,the node order of inflorescence,from the 3rd to the 5th,was 2-3 nodes lower than that of the CK.The fruit of plants treated in solutions with I- concentration of 2.0 mg·L-1 and high I- concentration(5.0-6.0 mg·L-1)ripened 5-8 days ahead of the CK.With respect to fruit setting rate,there was no significant difference between those plants treated with I- concentration of 1.0-4.0 mg·L-1 and the CK;but for plants treated with high I- concentration(5.0-6.0 mg·L-1),it was significantly lower
than the CK.The flower number,fruit number and yield with low I- concentration treatment(1.0-2.0 mg·L-1)were significantly larger than the CK,while the yield of plants treated with high I- concentration(5.0-6.0 mg·L-1)was significantly lower than the CK.Fruit weight decreased with the increase of I- concentration in solutions,but there was no significant difference between those treated with I- concentration of 1.0-3.0 mg·L-1 and the CK.To summarize these results,it can be concluded that the optimal I- concentration provided for cherry tomato growth should be 1.0-2.0 mg·L-1.
In order to study the effect of atmospheric pressure plasma on eggplant(Solanum melongena L.)growth and yield,the eggplant seeds were treated by equipment with different voltage from 4 420 to 6 800 V.The results showed that the plant height,plant extent,root length,root extent,single fruit weight and length etc.indexes were greater than the check(CK).In addition，the morbidity of eggplant cyanosis after treatment were lower than that of the control and the total yield were higher than the check.The highest yields were reached by the fifth,sixth and seventh treatments.Their yields were 11.59 %,11.0 % and 10.03 % than the check,respectively.