Clonal diversity,growth structure,and genetic diversity of 8 natural Syringa pinnatifolia var.alanshanica populations were assessed by ISSR molecular markers.Results showed that 16 ramets of 3 individual genets shared the same genotype,whereas 136 genotypes were differentiated among the other 239 samples from 7 populations.Clonal diversity revealed that S.pinnatifolia var.alanshanica was a phalanx clonal species and each population was composed of several clones.Most genets contained one ramet and the highest quantity of one genet consisted of 8 ramets.A relatively high clonal diversity of genotype Simpson's index(D=0.994) and distributional uniformity of genotype Fager's index(E= 0.985) was detected.Individuals per genotype(NC) and mean genotype proportion(PD) were 1.729 and 0.578,respectively,at the species level.In addition,high genetic diversity was detected at both population and species level.The coefficient gene differentiation(GST) was 0.320,indicating less differentiation among populations than within populations.

The seedlings of wheat('ML7113') were exposed to He-Ne laser irradiation(L) with 5 mW·mm-2 power density after enhanced UV-B radiation(10.08 kJ·m-2·d-1) to determine the mechanism of the action of nitric oxide on stomatal movement in wheat seedlings.The leaves and epidermal strips of wheat underwent different treatments by experiments for pharmacology and laser scanning confocal microscopy.The results showed that(1) Enhanced UV-B radiation not only induced stomatal closure,but also increased the levels of NO significantly in the guard cells and leaves of wheat.In addition,NO scavenger cPTIO obviously inhibited stomatal closure induced by UV-B radiation and the levels of NO evidently reduced in guard cells and leaves of wheat.(2) There were obvious differences in the effect of nitric oxide synthase(NOS) inhibitor L-NAME on stomatal aperture,NO content in guard cells and leaves of wheat exposed to enhanced UV-B radiation compared with nitrate reductase(NR) inhibitor NaN3.This suggested that nitric oxide synthase was the main way to produce NO in wheat leaves by UV-B radiation.(3) For stomatal aperture,LCKBLB.For the NO level,BBLCKL.For activity of NR and NOS,NR activity in the UV-B radiation treatment group was the lowest and He-Ne laser irradiation treatment group was the highest;however,NOS activity between B and L showed the opposite pattern compared with NR acti-vity.The stomatal opening changes induced by UV-B radiation and He-Ne laser irradiation were associated with high and low NO content in guard cells and leaves of wheat.Decreases and increases in stomatal aperture were consistent with increases and decreases in NO content.Furthermore,NO generation was the same as nitric oxide synthase in wheat leaves by He-Ne laser individual irradiation.

Using six inbred line cauliflower(Brassica oleracea Linn.var.botrytis Linn.) varieties from the Yangtze River basin as parents,general combining ability(GCA),specific combining ability(SCA) and correlation of primary characters such as head height,head diameter,head weight,maturity traits,bracts ratio and leaf coverage ratio were studied by 6 × 6 complete diallel cross and Griffing method I.Results showed that six characters were affected by additive and non additive effects.Maturity,bracts ratio,head height and leaf coverage ratio significantly affected by additive gene were mainly inherited by GCA;head diameter and head weight were mainly inherited by SCA and were strongly controlled by non-additive genes.Narrow heritability ranked in the order of maturity,bracts rate,leaf coverage ratio,head height,ball diameter and head weight.Concurrent selection of couple traits were head height and head weight,head diameter and head weight,head height and maturity,head weight and leaf coverage ratio,maturity and leaves coverage ratio;but independent selection of couple traits were head height and bracts ratio,head height and leaf coverage ratio,head diameter and maturity,head diameter and bracts ratio,head weight and bracts ratio,maturity and bracts ratio,bracts ratio and leaf coverage ratio.None interacted,and more traits of good characters were combined in the same cultivar.In the six inbred lines,P2 and P5 were ideal parental lines,and P4 was an ideal parental line for cold tolerance.The traits of P2×P4 in combination had better expression and SCA.

Asparagus officinalis Geland is highly resistant to stem blight and was used to study the effect of different auxins and cytokines on callus induction and multiplication of buds and rooting.Results showed that the best culture medium for callus induction was MS + 6-BA 0.3 mg/L + 2,4-D 1.5 mg/L +Sucrose 25 g/L +Agar 7 g/L,pH 5.8.The best culture medium for callus proliferation and shoot induction was MS+NAA 0.3 mg/L +6-BA 0.5 mg/L +Sucrose 30 g/L +Agar 7 g/L,pH 5.8.The best culture medium for root induction was 1/2 MS+0.5 mg/L IBA+1 mg/L PP333+ 0.3 mg/L 6-BA+ Sucrose 30 g/L+Agar 7g/L,pH 5.8.

Gateway molecular cloning technology was developed by Invitrogen based on the mechanism of site-specific recombination between λ phage DNA and the Escherichia coli genome.Construction of an expression vector for a target gene via Gateway LR reaction does not need to use restriction enzymes and a ligase,and thus is time efficient.Recently,to expand the application of Gateway technology in plant genetic engineering,several research groups have constructed Gateway destination vectors for studies on constitutive,inducible or silence expression of target genes,promoter analyses,protein localization,protein/protein interaction,DNA fragment modular assembly and functional verification of genomic fragments.Here we review research progress on the development of these destination vectors.