Comparative Study on Biological and Commercial Characteristics of Multiple Varieties of Broccoli(Brassica oleracea L.var.italica Plenck)and Vegetable Soybean(Glycine max(L.)Merr.)

[Objectives]This study was conducted to select vegetable soybean varieties(Glycine max(L.)Merr.)that are suitable for local cultivation and meet export requirements.[Methods]Through continuous years of comparative experiments on broccoli and vegetable soybean varieties,detailed biological characteristic and economic quality data of multiple varieties were obtained.[Results]Vegetable soybean variety Taiwan 75-3 had very prominent early-maturing trait,the highest quality(qualification rate),and higher yield than the control check(CK);and the early-maturing trait of vegetable soybean variety Kaohsiung 9 was also prominent,and its yield was higher than that of the CK.They could be promoted as the main vegetable soybean varieties for spring open field cultivation in this region.Among the tested broccoli varieties,Lake had a higher yield,and was relatively tolerant to cold.It had an early harvest period,and was planted as an early autumn variety in this region.Naihan Youxiu showed the highest yield,good quality,cold resistance,and strong adaptability,making it suitable for planting as a late autumn variety in this region.[Conclusions]This study provides technical guidance for the cultivation of local broccoli and vegetable soybean.

Putrescine Plays a Positive Role in Salt-Tolerance Mechanisms by Reducing Oxidative Damage in Roots of Vegetable Soybean

Polyamines play important roles in plant tolerance to environmental stress. With the aim of investigating the possible involvement of putrescine （Put） in salt-tolerance mechanisms in vegetable soybean roots, exogenous Put （10 mmol L＂） and its biosynthetic inhibitor D-arginine （D-Arg） （0.5 mmol L-1） were added to nutrient solution when vegetable soybean （Glycine max L. cv. Huning 95-1） seedlings were exposed to 100 mmol L^-11 sodium chloride （NaCl）. The results showed that Put ameliorated but D-Arg aggravated the detrimental effects of NaCl on plant growth and biomass production. Under NaCl stress, levels of free, soluble conjugated and insoluble bound types of Put in roots of vegetable soybean were reduced, whereas those of free, soluble conjugated, and insoluble bound types of spermidine （Spd） and spermine （Spm） were increased. Exogenous Put eliminated the decrease in Put but promoted the increase of Spd and Spm. However, these changes could be reversed by D-Arg. Under NaCl stress, activities of arginine decarboxylase （ADC）, S-adenosylmethionine decarboxylase （SAMDC）, diamine oxidase （DAO）, and polyamine oxidase （PAO） were induced, with exogenous Put promoting and D-Arg reversing these changes. Furthermore, NaCl stress decreased activities of antioxidant enzymes. Exogenous Put alleviated but D-Arg exaggerated these effects of NaCl stress, resulting in the same changes in membrane damage and reactive oxygen species （ROS） production. These results indicated that Put plays a positive role in vegetable soybean roots by activating antioxidant enzymes and thereby attenuating oxidative damage.

Effect of 1-MCP on Senescence and Decay of Vegetable Soybean Pods During Storage

The effects of 1-MCP on decay and senescence in vegetable soybean pods during storage were investigated. Treatments with 0. 5,1, or 2μl L-1 1-MCP significantly inhibited the senescence process of harvested vegetable soybean pods, as manifested in lower levels of ethylene production, respiratory rate, MDA and superoxide contents and higher levels of SOD, ASA-POD activities, Vc and chlorophyll contents. Moreover, 1-MCP promoted PAL activity and lignin synthesis, inhibited decay incidence. 2μl L-1-MCP treatment, however, inhibited PAL activity during the later period of storage, thereby increasing decay incidence.

Oxygation Enhances Growth,Gas Exchange and Salt Tolerance of Vegetable Soybean and Cotton in a Saline Vertisol

Impacts of salinity become severe when the soil is deficient in oxygen. OxygaUon （using aerated water for subsurface drip irrigation of crop） could minimize the impact of salinity on plants under oxygen-limiting soil environments. Pot experiments were conducted to evaluate the effects of oxygation （12% air volume/volume of water） on vegetable soybean （moderately salt tolerant） and cotton （salt tolerant） in a salinized vertisol at 2, 8, 14, 20 dS/m ECe. In vegetable soybean, oxygation increased above ground biomass yield and water use efficiency （WUE） by 13% and 22%, respectively, compared with the control. Higher yield with oxygation was accompanied by greater plant height and stem diameter and reduced specific leaf area and leaf Na^＋ and CI^- concentrations. In cotton, oxygation increased lint yield and WUE by 18% and 16%, respectively, compared with the control, and was accompanied by greater canopy light interception, plant height and stem diameter. Oxygation also led to a greater rate of photosynthesis, higher relative water content in the leaf, reduced crop water stress index and lower leaf water potential. It did not, however, affect leaf Na^＋ or CI^- concentration. Oxygation invariably increased, whereas salinity reduced the K^＋： Na^＋ ratio in the leaves of both species. Oxygation improved yield and WUE performance of salt tolerant and moderately tolerant crops under saline soil environments, and this may have a significant impact for irrigated agriculture where saline soils pose constraints to crop production.

Determination of the genetic diversity of vegetable soybean [Glycine max(L.) Merr.] using EST-SSR markers

The development of expressed sequence tag-derived simple sequence repeats(EST-SSRs) provided a useful tool for investigating plant genetic diversity.In the present study,22 polymorphic EST-SSRs from grain soybean were identified and used to assess the genetic diversity in 48 vegetable soybean accessions.Among the 22 EST-SSR loci,tri-nucleotides were the most abundant repeats,accounting for 50.00% of the total motifs.GAA was the most common motif among tri-nucleotide repeats,with a frequency of 18.18%.Polymorphic analysis identified a total of 71 alleles,with an average of 3.23 per locus.The polymorphism information content(PIC) values ranged from 0.144 to 0.630,with a mean of 0.386.Observed heterozygosity(H o) values varied from 0.0196 to 1.0000,with an average of 0.6092,while the expected heterozygosity(H e) values ranged from 0.1502 to 0.6840,with a mean value of 0.4616.Principal coordinate analysis and phylogenetic tree analysis indicated that the accessions could be assigned to different groups based to a large extent on their geographic distribution,and most accessions from China were clustered into the same groups.These results suggest that Chinese vegetable soybean accessions have a narrow genetic base.The results of this study indicate that EST-SSRs from grain soybean have high transferability to vegetable soybean,and that these new markers would be helpful in taxonomy,molecular breeding,and comparative mapping studies of vegetable soybean in the future.

Nutritional quality of different potassium efficiency types of vegetable soybean as affected by potassium nutrition

Pot experiments were conducted in 2017,2019,and 2020 to examine the effects of potassium nutrition on the nutritional components of vege-table soybeans with different K efficiency at immature and mature stages.Two vegetable soybean varieties with higher K efficiency and two varieties with lower K efficiency were studied in the low available K soil under the conditions of no K and normal K fertilization.The results indicated that almost all nutritional components in vegetable soybean were affected by K,genotypes,interannual differences,and their inter-actions.In general,no K fertilization increased protein and amino acid concentrations but decreased oil,soluble sugar,sucrose,K,Mg,and Fe concentrations in immature and mature vegetable soybean.The sensitivity of nutritional components to K nutrition differed among varieties.For instance,K high-efficiency varieties generally exhibited higher protein and amino acid concentrations without K application.K high-efficiency vegetable soybeans are low-K tolerance varieties to isoflavones.The results of this study provide insights for high yield and quality vegetable soybean breeding against soil K deficiency.

Changes in the sugars,amino acids and organic acids of postharvest sperminetreated immature vegetable soybean(Glycine max L.Merr.)as determined by^(1)H NMR spectroscopy

^(1)H NMR spectroscopy was adopted to determine compositional changes(mainly sugars,organic acids and amino acids)involved in cold-stored immature soybean grains after exogenous spermine treatment.Significant changes of sugars,including sucrose,galactose,myo-inositol,glucose and fructose were detected in soybean after spermine treatment.As for the organic acids related to tricarboxylic acid cycle,the levels of malic and fumaric acids decreased but the level of citric acid increased.However,no significant changes were observed for amino acids in spermine-treated soybeans.By using metabolic profile analysis,a difference was observed between the aging of soybean grains as such and those treated with spermine.This study provides an insight into the accumulation of metabolites in postharvest immature soybeans after exogenous spermine-treatment.

SUMO E3 Ligases GmSIZ1a and GmSIZ1b regulate vegetative growth in soybean

SIZ1 is a small ubiquitin-related modifier（SUMO） E3 ligase that mediates post-translational SUMO modification of target proteins and thereby regulates developmental processes and hormonal and environmental stress responses in Arabidopsis. However,the role of SUMO E3 ligases in crop plants is largely unknown. Here, we identified and characterized two Glycine max（soybean） SUMO E3 ligases, GmSIZ1a and GmSIZ1b. Expression of GmSIZ1a and GmSIZ1b was induced in response to salicylic acid（SA）, heat, and dehydration treatment, but not in response to cold, abscisic acid（ABA）, and Na Cl treatment. Although GmSIZ1a was expressed at higher levels than GmSIZ1b, both genes encoded proteins with SUMO E3 ligase activity in vivo.Heterologous expression of GmSIZ1a or GmSIZ1b rescued the mutant phenotype of Arabidopsis siz1-2, including dwarfism, constitutively activated expression of pathogen-related genes, and ABA-sensitive seed germination.Simultaneous downregulation of GmSIZ1a and GmSIZ1b（GmSIZ1a/b） using RNA interference（RNAi）-mediated gene silencing decreased heat shock-induced SUMO conjugation in soybean. Moreover, GmSIZ1 RNAi plants exhibited reduced plant height and leaf size. However,unlike Arabidopsis siz1-2 mutant plants, flowering time and SA levels were not significantly altered in GmSIZ1 RNAi plants. Taken together, our results indicate that GmSIZ1a and GmSIZ1b mediate SUMO modification and positively regulate vegetative growth in soybean.