In order to further reveal the mechanism of GA signal transduction in apple(Malus × domestica) and the physiological function of MdDELLAs,a gene named MdRGL3a(GenBank:DQ007887)cloned from‘Royal Gala’was analyzed. The function of this gene was analyzed by ectopic expression of MdRGL3a in Arabidopsis thaliana. Real-time quantitative PCR results showed that MdRGL3a was expressed in different tissues,and the expression level was higher in flowers and fruits. Ectopic expression of MdRGL3a in Arabidopsis thaliana reduced response to GA3,which exhibited shorter root and hypocotyl,slower germination,smaller leaves and shorter stalk. The result of Arabidopsis thaliana plants treated with GA3 showed that MdRGL3a reduced the promotion of GA for plants growth and development,revealing that MdRGL3a might be a negative regulator of GA signaling pathway.
In order to determine the suitable time for 5-aminolevulinic acid(5-ALA)application to alleviate salinity injury in strawberry(Fragaria × ananassa Duch.‘Benihoppe’),exogenous 10 mg ? L-1 5-ALA solution was rhizospherically applied at 5 days before,simultaneously or 3 days after 100 mmol ? L-1 NaCl treatment,and the results showed that the alleviating effect was best in the pretreatment. This result implies that 5-ALA is more preventive than therapeutic for strawberry against salt stress. After then,another experiment was carried out,where 10 mg ? L-1 5-ALA solutions were rhizospherically pretreated to strawberry plants 5,10,15 or 20 days before NaCl treatment and the result showed that the pretreatment prior 20 d was the best effective treatment,which means that the earlier the strawberry was pretreated with 5-ALA,the less of salinity injury was found. It was observed that the possible alleviating mechanisms of 5-ALA against salt stress in strawberry may include the follows. (1) 5-ALA alleviated the decrease of leaf chlorophyll content and Chl.b/a ratio induced by salinity in strawberry. (2) 5-ALA induced the additional increase of antioxidant enzyme activities and decreased the production rate of superoxide anion in the leaves and roots of strawberry under salt stress. (3) 5-ALA was beneficial to intersystem electron transport from PSⅡ to PSⅠ,increasing the energy conversion efficiency during light energy absorption,harvest and transport,reducing heat dissipation,and improving photosynthetic capacity under salt stress. (4) 5-ALA alleviated the inhibition of plant growth induced by salt stress,including shoots and roots,especially the latter.
On the basis of gene sequence analysis of the strawberry alkaline/neutral invertase gene family(Fa.A/N-Inv),strawberry cultivars‘Shen Yang’and‘Benihoppe’were employed as materials. The expression patterns of Fa.A/N-Inv genes under different conditions were analyzed by qRT-PCR. The dynamic enzyme activity of A/N-Inv and the sugar accumulation during fruit development stages were determined by spectrophotography and high-performance liquid chromatography(HPLC),respectively. Eight members of alkaline/neutral invertases were identified in the strawberry genome. The expression patterns of 4 Fa.A/N-Inv genes are tissue-,developmental stage-,and genotype-specific. The expression of 4 Fa.A/N-Invs was differentially induced by cytokinin(BA),gibberellic acid(GA)and auxin(IAA). Sucrose and glucose,as substrate and product of A/N-Inv,hold positive and negative feedback regulation on expression of the 4 genes,respectively. Besides,as a signal molecule,sucrose could induce the expression of Fa.A/N-Inv genes. The enzyme activity of A/N-Inv in‘Shen Yang’was higher than that in‘Benihoppe’fruits of all stages except for the green fruit. The content of sucrose in ripe ‘Benihoppe’fruit(50.7 mg · g-1 FW)was double of that in‘Shen Yang’fruit(23.2 mg · g-1 FW).
The variable characteristics of the plant growth,yield,quality,K+ and Na+ uptake and distribution,and photosynthesis were measured in the same scion‘Jiaxina 74-112’tomato grafted on 8 different rootstocks and the self-root grafting plants. Effects of both grafting and salt stress on plants yield,quality and salt stress tolerance were comprehensively evaluated on the basis of membership values of above indexes calculated by the method of membership function. The results showed that the plant growth and yield were significantly inhibited by salt stress. However,the fruit quality was significantly improved
In order to improve the accumulation of steroidal glycoalkaloids(SGAs) in the aerial part of potato cultivar and thus to enhance its resistance and tuber quality improvement,the solanidine rhamnosyltransferase(sgt3)gene and ribulose-1,5-bisphoshate carboxylase(Ruisco)promoter were cloned in this research. Subcellular localization prediction showed that SGT3protein did not contain chloroplast transit peptide,mitochondrial peptide and signal peptide sequence. Therefore,we speculated that SGT3 protein was located in the cytoplasm. Furthermore,cDNA fragment of sgt3 and rbcS promoter was recombinated into plasmid pCEPSP. And we got a plant vector with glyphosate resistance marker that has sgt3 gene driven by a green-tissue promoter rbcS(rbcS:sgt3). In addition,Longshu 3 and Shepody were transformed by Agrobacterium-mediated protocol,and we obtained 12 glyphosate-tolerant transgenic plantlets. The analysis of gene expression levels indicated that the relative expression of sgt3 transcript in transformation plantlets were higher(1.3–3.0 times)than non-transformation plantlets. Also,the content of SGAs has increased by 20% to 37% for all transformation plantlets. Whereas,SGAs content did not display a significant difference between transgenic tuber and non-transgenic tuber in potato. Our result of this study will provide a theoretical basis for breeding varieties with SGAs content enriched in the foliage but diminished in the tuber in the further.
Genetic relationship amongst the 6 cultivars of cut chrysanthemum and their 38 F1 hybrids derived from a 2 × 4 incomplete diallel cross was unraveled by SRAP markers. The SRAP genotyping suggested that of the 229 fragments produced by 17 SRAP primer combinations 127 were polymorphic,with an average of 7.5 polymorphic fragments per primer combination,thus indicative of a moderate molecular diversity present in the entries. The Nei’s genetic distances were estimated between 0.11–0.25 and averaged at 0.19,denoting a close genetic relationship among the parental cultivars. The SRAP-based genetic similarity was calculated at 0.42–0.72 and 0.40–0.85,respectively,for the parental cultivars and the F1 hybrids,and the median of genetic similarity(0.61)for the hybrids were higher than that(0.55)for parental cultivars. This suggests a narrowing genetic base or homogenization during hybridization in chrysanthemum,despite the occurrence of some variant lines. Based on genetic similarity matrix,the UPGMA clustering classified the investigated entries into two major groups well congruent with female parents and cross combinations,reinforcing the reliability of SRAP markers in distinguishing F1 hybrids resulted from different combinations in chrysanthemum.
The leaf color of the upper,middle and lower leaves of 62 ornamental crabapple cultivars were observed by X-rite color difference meter. The dynamic changes of the color of different cultivars in the growing season were studied,and established the evaluation system of the leaf color of the crabapple,on this basis,the fine foliage breed were selected. (1) Based on the L*,C*,h°,three-dimensional dynamic figure of CIELCH color space at different leaf positions were built. All varieties of the upper leaves of the most abundant color,L*,C*,h° sites are the most dispersed,the middle leaf color has faded;L*,C* showed a continuous downward trend,h° showed an increasing trend;the lower leaf color becomes dark green,L*,C*were the lowest and h°were the highest. (2) Based on the color parameter(L*,a*,b*)of upper leaves in May,the tree diagram of the leaf color cluster analysis was built. We found that 62 ornamental crabapple were divided into 2 major groups and 5 subgroups,including Green group(Dark green,Brownish green and Bright green)and Red group(Fuchsia and Reddish brown). (3) Based on the results of cluster analysis and color parameters,the evaluation system and the evaluation system of leaf germplasm of ornamental crabapple were established. We found that M.‘Spring Snow’,M.‘Golden Raindrop’and M. floribunda were bright beautiful and have a high color regularity,this three cultivars were the fine germplasm in green group. In red group,M.‘Perfect Purple’,M.‘Purple Gems’,M.‘Thunderchild’,M.‘Cardinal’were red and beautiful and had a high level in regularity and stability,this four cultivars were the fine germplasm in red group.
The effects of phloridzin and phloretin(typical phenolic acids in the soil of apple orchard) on the plant biomass,root activity,protective enzyme activities and the content of malondialdehyde(MDA)of one year Prunus persica grafted seedlings were studied under pot condition. The results showed that phloridzin could significantly damage the Prunus persica grafted seedlings,compared with the control,the fresh and dry weight reduced by 16.66% and 21.58%,respectively. The root activity reduced by 33.04%,and the activities of superoxide dismutase(SOD)and peroxidase(POD)reduced by 40.80% and 31.10%,while the content of MDA increased by 116.34%. Phloretin had little effect on the Prunus persica grafted seedlings. Potassium permanganateobviously alleviated the damage of phloridzin to Prunus persica grafted seedlings,significantly reduced the content of phloridzin in the apple orchard soil by 57.80%,improved the biomass,root activity,protective enzyme activities of the peach seedlings and reduced the content of MDA. In conclusion,phloridzin(0.343 mg · kg-1)measured in old apple orchard soil could reduced the biomass of the peach seedlings,and moderate potassium permanganate could alleviate the damage of phloridzin on the peach seedlings.
In order to learn the seed hardness of pomegranate during development,the soft seeds cultivar‘Tunisia’,the semi-soft seeds cultivar‘Israel Sour’and the hard seeds cultivar‘Qingpi’were used in this research. The seed hardness,aril weight and total soluble solids in pulpa were tested during development. The cell microstructure and lignifying conditions in seed coat were also observed during fruit ripening,under microscope by phloroglucinol-HCl and safranine staining. The seed hardness of ‘Tunisia’growing at different places was also compared. Results showed that the seed hardness of pomegranate increased progressively during ripening. The maximum hardness stage was presented at the later stage of fruit ripening but not at the completely ripened time. On the 97th d after flowering,the seed hardness of‘Tunisia’arrived its maximum,(2.939 ± 0.895)kg,while‘Israel Sour’and‘Qingpi’got their maximum seed hardness,with being(5.571 ± 2.109)and(9.203 ± 3.006)kg,respectively,on the 106th d after flowering. On the 124th d after flowering,the maturity,the seed hardness of‘Tunisia’,‘Israel Sour’and‘Qingpi’was(2.887 ± 0.735),(4.242 ± 1.036)and(8.192 ± 2.561)kg,respectively. The seed hardness of the 3 cultivars showed significant difference. The correlation between seed hardness and total soluble solids and aril weight varied in a large range with TNS being the highest of them. No significant difference of seed hardness was detected among the seeds of TNS growing at different places at mature time. Micro-examination revealed that the cell wall of seed coat was highly lignified in the cultivars. According to the cell wall thickness of outer integument,order of the 3 cultivars was ranked as‘Tunisia’>‘Israel Sour’>‘Qingpi’. The significant differences were detected among the cultivars by ANOVA. In summary,TNS was a soft-seeded cultivar of pomegranate with significant lower cell wall thickness. The seed hardness was independent to the growing conditions.
The flavor and main nutritional quality of 3 wild populationsofAllium tuberosum Rottler production in southeastern Tibet were evaluated. The populations included Muxu and Quzika populations of Markham County,as well as Raojin population of Zogong County. The results showed that there were 21 kinds of amino acids in the 3 populations,and the content of glutamine(Gln)was the highest,followed by alanine(Ala),which accounted for 12.87%–22.03% and 10.33%–12.55% of total amino acids,respectively. The 8 essential amino acids for human body were at a low level,0.9431 mg · g-1 in Muxu population(accounting for 35.80%)0.7884 mg · g-1 in Quzika population(accounting for 36.61%)and 1.1895 mg · g-1 in Raojin population(accounting for 41.16%). Fourteen kinds of amino acids showed significant difference in different degree. Lower vitamin B1(around 0.3 μg · g-1)and vitamin B2(around 0.4 μg · g-1),higher vitamin A(around 10 μg · g-1)and vitamin E(from 3 to 13 μg · g-1)while rich vitamin C(around 1.5 mg · g-1)were detected in all the three populations. In contrast,the content of vitamin B6 was less than 0.1 μg · g-1 thus below the limit of detection. Ten kinds of aromatic substances were detected in Muxu and Quzika populations while 11 kinds of aromatic substances in Raojin population. Methyl mercaptan was only detected in Raojin population. It displayed difference in varying degree among the ten aromatic substances contained in the 3 populations. Dimethyl disulfide had the highest content among all the aromatic substances in the 3 populations,accounting for 70% of the aromatic substances. The content of soluble sugar,protein and water showed significant differences in varying degree among populations.
‘Liantong’,a new strawberry cultivar,was mutagenesised and selected with tissue culture technique from‘Tongzi 1’,under the pressure of the mixture consisted of toxin of Fusarium oxysporum f. sp. fragariae and 4-hydroxybenzoic acid,an autotoxin. The long and conical fruits are orange-red or red color,smooth in surface,waxy in luster,with a slight acid and strong fragrant in aroma,which contains 0.17% titratable acid,11.3% soluble solids,7.9% total sugar and 0.793 mg · g-1 vitamin C,with 2.325 kg · cm-2 fruit firmness and good shipping quality. The cultivar is resistant to wilt disease,gray mildew and powdery mildew,and suitable planted in open cultivation,semi-forcing or forcing cultivation in Hebei and Shandong provinces,with the yield more than 34 500 kg · hm-2. The occurrence of continuous cropping obstacle of‘Liantong’is lighter obviously than‘Tongzi 1’.