Effects of Different Nitrogen Fertilizer Rates on Soluble Sugar,Starch and Root Tissue Structure of the Peach Trees

[Objective] The research aimed to provide theoretical basis for the cultivation and production of peach.[Method] The three-year-old seedling peach tree was used as the materials,and NH4NO3 was used as the experimental nitrogen fertilizer.Three nitrogen levels,0,3,6 g per pot respectively were set to study the effects of different nitrogen fertilizer on the contents of soluble sugar,starch and internal structure of the root of the peaches.[Result] The contents of soluble sugar of roots and leaves increased with the increase of nitrogen fertilizer level,and the level of 6 g per pot was the highest,which showed extreme differences between the level of 3 g per pot and the control.However,starch contents showed opposite results,which decreased as the level of nitrogen fertilizer increased.Compared with the 3 g per pot level of nitrogen fertilizer and the control,the internal structure of root applied with nitrogen fertilizer of 6 g per pot level had larger fibrovascularcylinder,advanced vascular bundle,small-spaced thin-walled cells,smooth and full cells with smooth cell wall.[Conclusion]Appropriate nitrogen levels can accelerate the accumulation of soluble sugar and the growth of root tissue structure.

Effect of Alkali Stress on Soluble Sugar, Antioxidant Enzymes and Yield of Oat

Alkali stress can cause severe crop damage and reduce production. However, physiological processes involved in alkali stress in oat seedlings are not well understood. In this study, physiological responses and yield of oat to alkali stress were studied using the alkali-tolerant oat genotype Vao-9 and the alkali-sensitive oat genotype Baiyan 5. The results were： （i） low concentrations of alkali stress （25 and 50 mmol L^-1） significantly reduced the yield and grain weight while increased the oat grain number per spike. A negative correlation between yield and malondialdehyde （MDA） content at the jointing and grain filling stages and positive correlations between yield on one hand and superoxide dismutase （SOD）, and peroxidase （POD） activities on the other at the jointing stage were observed. There was a positive correlation between MDA and soluble sugar at the grain filling stage; （ii） soluble sugar content was increased at the jointing and grain filling stages and decreased at the heading stage by alkali stress; （iii） alkali stress increased the SOD activity during the heading and grain filling stages, and increased the POD activity at the heading stage. As compared to the control, the increase of MDA contents in alkali-treated oat was observed, during the jointing, heading and grain filling stages; （iv） under alkali stress, the oat genotype Vao-9 showed higher antioxidant enzyme activity and lower soluble sugar contents during the heading stage, and lower MDA contents than those in the oat genotype Baiyan 5 under alkali stress. The result suggested that the high ROS scavenging capacity and soluble sugar levels might play roles in oat response to alkali stress,

Changes of Oxidative Stress and Soluble Sugar in Anthers Involve in Rice Pollen Abortion Under Drought Stress

Two rice maintaining lines with different drought tolerances, viz., Jin 23B （tolerant） and Zhenshan 97B （sensitive）, were used to study the oxidative stress and soluble sugar in rice anthers and pollen viability under drought stress during flowering stage. Higher antioxidant enzyme activities and lower malonaldehyde （MDA） content in rice anthers were observed in Jin 23B than in Zhenshan 97B under drought stress. Further, a great increase in the content of soluble sugar in rice anthers of Jin 23B was observed across the whole drought exposure, while Zhenshan 97B showed significant decrease in soluble sugar during 9-12 d after drought stress （DADS）. Accordingly, a marked decline of pollen fertility and activity, pollen numbers in an anther and pollen numbers on a stigma was observed in Zhenshan 97B, whereas little difference was found in Jin 23B. Thus, we suggest that pollen abortion caused by drought stress may be related with the reciprocity between oxidative stress and soluble sugar content in rice anthers.

Effect of Cadmium and Herbicides on the Growth, Chlorophyll and Soluble Sugar Content in Rice Seedlings

To investigate the combined effects of Cd^2＋ （ 0,10,100,500 μmol/L） , acetochlor （AC） （0,1.6,4.0,8.0μmol/L）, and bensulfuronmethyl （BSM） （ 0,0.16,0.40,0.80 μmol/L） on the biomass,leaf soluble sugar, total chlorophyll （chl） content, chl a/b ratio, and Cd content in roots and shoots in the rice seedlings, pot culture experiments were conducted with rice （Oryza sativa L. ） cultivar Jinyou 402. The results showed that the Cd and AC combined treatment （Cd＋ AC treatment） significantly inhibited the growth of the roots and shoots. The root dry weight/shoot dry weight （RDW/SDW） ratio, total chlorophyll content and chl a/b ratio decreased by 41%, 50%, 56% , respectively, in comparison with the control, as well as the leaf soluble sugar content, plant dry weight /plant fresh weight （PDW/PFW） ratio increased by 284% and 44% , respectively. Cd content in the roots and shoots had a decreasing tendency with the increasing concentration of AC under the Cd＋AC treatment. The Cd and BSM combined treatment （Cd＋BSM treatment） had a similar result to the Cd＋AC treatment. The results suggest that the toxicity of Cd to rice seedlings has been enhanced due to its combination with herbicides.

Diallel analyses of soluble sugar content in cowpea (Vigna unguiculata L.Walp.)

The content of soluble sugar in cowpea(Vigna unguiculata L. Walp.) seeds is important for their acceptability to consumers. The objective of this study was to evaluate the genetic control of soluble sugar content in cowpea using diallel analysis. For this purpose,half-diallel crosses were made among seven diverse parents. The amount of total soluble sugar was estimated by the phenol sulfuric acid reagent method and reducing sugar were measured by the DNS(3,5-dinitrosalicylic acid) reagent method. The total soluble sugar ranged from 11.12(VYA) to 40.79 mg g^(-1)(IT93 K-693-2) with a mean of 22.31 mg g^(-1).Reducing soluble sugar showed a mean value of 9.11 mg g^(-1) and ranged from 13.61(TVx3236) to 4.98 mg g^(-1)(Lori niebe). Diallel analysis showed that both additive and non-additive gene effects were significant in the genetic control of these traits. However,dominance variance was greater than additive variance for soluble sugar. The traits were controlled mainly by an overdominance model, suggesting the advantage of delaying selection to later generations. Soluble sugar content was found to be highly heritable, with broad-sense heritability ranging from 0.987 to 0.976. Narrow-sense heritability ranged from0.154 to 0.422 and revealed the lower importance of additive variance. Parents and F_1 hybrids differed significantly on the basis of their general and specific combining abilities,respectively. Recessive alleles had positive effects on total soluble sugar and reducing soluble sugar. These results could help cowpea breeders improve the acceptability of cowpea seeds and cowpea-based foods by appropriate selection.

Effect of heat stress on the MDA, proline and soluble sugar content in leaf lettuce seedlings

High temperature stress on different varieties of lettuce seedlings in MDA, proline and soluble sugar content were studied. The results were as follows : With the stress temperature, varieties of leaf lettuce seedlings in the MDA, proline and soluble sugar content gradually increased;Different varieties had the most significant difference in 38/33℃(d/n). The increase of heat-resistant varieties on proline and soluble sugar content was quick and high, while its increase in MDA content was slow and small.

Screening of Seed Soluble Sugar Content in Cowpea (<i>Vigna unguiculata</i>(L.) Walp)

Cowpea (Vigna unguiculata (L.) Walp) is a legume crop grown worldwide to provide protein, starch, soluble sugar, amino acids, fatty acids, minerals, and vitamins for human consumption and animal feed. Soluble sugar is an important physiological trait in cowpea seeds. It not only plays an important role in storability and abiotic stress tolerance in seeds, but also provides energy to the human body and improves cooking quality by giving a desirable taste and mouth feel. Therefore, this research aimed to evaluate variation of cowpea seed soluble sugar content, and assess the soluble sugar content of cowpea varieties with different seed coat colors for cowpea consumers. A total of 113 cowpea genotypes were used, including 89 USDA GRIN germplasm accessions and 24 advanced breeding lines developed from University of Arkansas, AR, USA. Seed soluble sugar content was measured using a Spectrophotometer by phenol-sulphuric acid method. The results showed that the seed soluble sugar contents among 113 cowpea genotypes exhibited a wide range varying from 32.6 mg/g to 86.1 mg/g with an average of 54.5 mg/g. The five highest soluble sugar contents in seeds were found in the Arkansas cultivar Empire (86.1 mg/g), USDA germplasm accession PI583202 (84.5 mg/g), Arkansas advanced breeding line 09-655 (82.1 mg/g), USDA accession PI601085 (81.6 mg/g), and Arkansas advanced breeding line 09-529 (80.9 mg/g), and they can be used in cowpea breeding programs to develop new cowpea cultivars with higher seed soluble sugar content. It was also observed that the soluble sugar contents in Arkansas commercial cultivars and advanced breeding lines were higher than those in USDA germplasm and the seeds with colorful coat may have soluble sugar levels desirable by consumers.

Change of 3 Kinds of Enzyme Activity and Soluble Sugar in 3 Chinese Cabbage Varieties with Different Resistance Level During the Process of Plasmodiophora brassicae Infecting Their Roots

There are different levels of resistance in Chinese cabbage varieties against clubroot.The content of catalase(CAT),peroxidase(POD),phenylalanin ammonia-lyase(PAL),Super Oxide Dismutase(SOD)and soluble sugar activities of 3cultivars with different clubroot-resistant levelswere detected after inoculation in this study.The results suggest that the changing rates of CAT,PAL and SOD contents of resistance cultivars after inoculation were higher than those of susceptible cultivars(Baigengbaiye>Zaobaicaitai>Huangjinxiaobaicai);the POD activities of resistance cultivars reached a peak on an earlier day than those of susceptible cultivars;the increasing rate of soluble sugar of susceptible cultivars was higher than that of the resistance cultivars,and ended with two peaks.Therefore,the four enzymes(CAT,POD,PAL and SOD)and soluble sugar may be used as physiological and biochemical reference indexes for the resistance identification to clubroot after inoculation with P.brassicae.

Identification of candidate genes related to soluble sugar contents in soybean seeds using multiple genetic analyses

Soluble sugar content in seeds is an important quality trait of soybean. In this study, 57 quantitative trait loci(QTLs) related to soluble sugar contents in soybean seeds were collected from databases and published papers. After meta-overview-collinearity integrated analysis to refine QTL intervals, eight consensus QTLs were identified. To further verify the consensus QTLs, a population of chromosome segment substitution lines(CSSLs) was analyzed. Two lines containing fragments covering the regions of consensus QTLs and the recurrent parent were selected: one line showed high soluble sugar contents associated with a consensus QTL fragment, and the other line showed low soluble sugar contents. Transcriptome sequencing was conducted for these two lines at the early, middle, and late stages of seed development, which identified 158, 109 and 329 differentially expressed genes, respectively. Based on the analyses of re-sequencing data of the CSSLs and the consensus QTL region, three candidate genes(Glyma.19 G146800, Glyma.19 G122500, and Glyma.19 G128500) were identified in the genetic fragments introduced from wild soybean. Sequence comparisons between the two CSSL parents SN14 and ZYD00006 revealed a single nucleotide polymorphism(SNP) mutation in the coding sequence of Glyma.19 G122500, causing a nonsynonymous mutation in the amino acid sequence that affected the predicted protein structure. A Kompetitive allele-specific PCR(KASP) marker was developed based on this SNP and used to evaluate the CSSLs. These results lay the foundation for further research to identify genes related to soluble sugar contents in soybean seeds and for future soybean breeding.

The difference of soluble sugar contents and starch synthetic key enzyme activities between high and low starch cultivar of cassava

The difference of soluble sugar contents and starch synthetic key enzyme activities between high starch cultivar and low starch cultivar were studied in this experiment, of which FuXuan01, GR891, SC124, and SC201 were used as materials. The results showed that the contents of reducing sugar in root tube of low starch cultivars were higher than those of high starch cultivars in all growth periods, the contents of sucrose in root tube of high starch cultivar were higher than those of low starch cultivars in the early growth period, but, lower in the late growth period, and there were almost no difference in the contents of soluble sugar in root tube between high starch cultivar and low starch cultivar in the early growth period, but notable difference in the late growth period and the soluble sugar contents of low starch cultivars were higher than those of high starch cultivars. It also-showed that the activities of ADPGPpase, SSS, and SBE （starch branching enzyme） of high starch cultivars were higher than those of low starch cultivars. It was evident that there were close correlations between the content of sucrose, reducing sugar and soluble sugar in root tube, and the activities of ADPGPpase, SSS, SBE, and the starch accumulation in the root tubers of cassava. It was quite evident in this experiment that the soluble sugar and starch synthetic key enzyme were main factors controlling starch accumulation in root tubers. These results provided important indication for physiological controlling in high starch cultivation and gene engineering breeding of high starch cultivar of cassava.

Effects of NaOH Treatment on Fiber, Crude Protein and Soluble Sugar Content of Corn Straw

[Objective] The paper was to study the effects of different levels of NaOH on fiber, crude protein and soluble sugar content of cornstraw. [Method] Four treatments were designed in the test, namely control group, group 1, group2 and group 3, which were added with 0, 2%, 3%and 4% NaOH according to the dry weight of corn straw, and the moisture of corn straw after treatment was 45%. After being treated at room tem-perature for 48 h, sensory evaluation and nutrient composition analysis were performed for each group, and the contents of neutral detergent fiber（NDF）, acid detergent fiber （ADF）, crude protein （CP） and soluble sugar （SS） were measured. [Result] With the increasing addition level of NaOH,the content of NDF and ADF decreased gradually, and significant differences were observed between group 3 （adding 4% NaOH） and control group（P〈0.05）. There was no significant difference in CP content among treatment groups（P〉0.05）; the SS content gradually increased, and there weresignificant differences between treatment groups and control group （P〈0.05）. [Conclusion] 4% NaOH reduced the fiber content and increased thesoluble sugar content of corn straw.

Adsorption Behavior of a Water-soluble Porphyrin at the Glass-water Interface as Studied by Synchronous Total Internal Reflection Fluorescence Spectroscopy

Total internal reflection fluorescence spectroscopy (TIRF) and synchronous scanning technique were combined to study the adsorption behavior of the meso-tetrakis (4-sulfonatophenyl) porphyrin (TPPS) at the glass-water interface without any surfactant. The pH dependence of synchronous fluorescence signal at the interface was analyzed. Both unprotonated (TPPS4-) and diprotonated (H2TPPS2-) forms of TPPS were observed at the interface. But the interface favored the adsorption of. The apparent estimated pKa2 value shifted from 5.00 in the bulk solution to 2.7 at the interface. STIRF provides a good technique to study multi-component systems at the interface.

Profiling seed soluble sugar compositions in 1164 Chinese soybean accessions from major growing ecoregions

Soluble sugar is a key quality trait of soybean seeds.We developed rapid and economic extraction and quantification methods for seed soluble sugars using an ultra-high performance liquid chromatography system with a refractive index detector.We evaluated the soluble sugar compositions of 1164 soybean accessions collected from diverse ecoregions and grown in multiple locations and years.Total soluble sugar(TSS)content was influenced by accession type,year of cultivation,and ecoregion.The mean contents of fructose,glucose,sucrose,raffinose,stachyose and TSS were 3.31,5.21,55.60,6.60,35.47,and 106.19 mg g^(-1),respectively.The highest mean TSS content(108.71 mg g^(-1)) was observed in accessions from Northern Region of China.Cultivars contained higher contents of sucrose,raffinose,and TSS,whereas landraces had a higher content of stachyose.Fourteen accessions with mean TSS contents>130 mg g^(-1) were identified as elite soybean resources.TSS was correlated with sucrose,raffinose,stachyose,protein,oil and total tocopherol.The main soluble sugar components were correlated with latitude and longitude,indicating that the geographical origin of the accessions affected their seed soluble sugar compositions.The developed methods and elite identified accessions can be used in the food and feed industry and in soybean breeding programs aimed at improving soybean seed nutrition.

Change in ^(14)C-soluble Sugar Involved in the Photosynthate Translocation Pathway of Tomato

Liaoyuanduoli tomato was planted in pots in a solar greenhouse. The first leaf below the second cluster was labeled by ^14CO2 with a dose of 0.555 MBq 30 days after the second cluster anthesis. Mesophyll, midrib, petiole vascular of the fed leaf, internode vascular below the fed leaf （adjacent to the fed leaf）, peduncle vascular of the second cluster, sepal, fruit pedicle, pulp, pectinic, and dissepiment were taken 2, 4, 8, 12, 20, 24, 48, and 72 h, respectively, after ^14CO2 feed to determinate the composition and specific activity of carbohydrate at different sites and different time after the labeling. The results indicated that almost all of the photosynthates resulting from 1 h of photosynthesis could be transported out of the leaf within 72 h and more than 85% of them were exported within 24 h. The greatest amount of sucrose transport occurred in the internode pedicel vascular bundle 8 h after the start of photosynthesis. Assimilates entering the fruit through the internode and pedicel vascular bundles were detectable but in small quantities 2 h after photosynthesis. Only the radio activity of sucrose but not that of glucose and fructose was detected, suggesting that some of the sucrose in the fruit came directly through the phloem at an early stage of fruit development, not through the synthesis of glucose and fructose. Fruit vascular may be the part where sucrose first metabolized after it entered the fruit.

紫果西番莲‘满天星’二倍体与三倍体生长生理指标的比较

以紫果西番莲‘满天星’二倍体与三倍体无菌苗为研究材料,测定不同年度生长阶段的生长和生理指标,比较其差异性,并进行相关性分析。结果表明:2种‘满天星’苗木的苗高、地径持续增长,表现出三倍体‘满天星’苗高较小、地径较大的特点。同一位置叶片的叶片长、叶片宽、叶柄长随时间变化呈先增大后减小的趋势。随时间的变化2种‘满天星’的茎节数量逐渐一致,三倍体‘满天星’苗木表现出短粗的特征。在测定期中三倍体‘满天星’可溶性蛋白和叶绿素含量大于二倍体,测量前期可溶性糖含量小于二倍体,后期大于二倍体。不同倍性的西番莲的叶绿素a、叶绿素b、类胡萝卜素与苗高、茎节、地径呈负相关,与叶长、叶柄长呈正相关;但可溶性糖、可溶性蛋白与生长指标相关性略有差异。综上所述,三倍体与二倍体的生长生理指标存在差异,且可溶性糖、可溶性蛋白与生长指标相关性存在差异。

大豆地方种质资源鲜籽粒可溶性糖含量的全基因组关联分析

【目的】可溶性糖含量是鲜食大豆重要的品质性状之一,研究大豆鲜籽粒可溶性糖含量的遗传变异,深入解析可溶性糖含量的遗传机制,为鲜食大豆种质创新及品质育种提供依据。【方法】利用来自东北大豆生态区、北方大豆生态区、黄淮海大豆生态区和南方大豆生态区的133份大豆地方种质,在2021年连江春季、福清春季和秋季3个环境下对鲜籽粒可溶性糖含量进行表型测定,结合82187个高质量SNP标记,基于混合线性模型MLM(Q+K)对可溶性糖含量进行全基因组关联分析,挖掘可溶性糖含量显著相关的SNP位点,并以显著SNP位点为中心,两端各扩展119.07 kb连锁不平衡衰减距离为候选区间,根据候选区间内基因的注释和组织表达信息预测候选基因。【结果】3个环境下,鲜籽粒可溶性糖含量的变异范围为3.37—33.84 mg·g^(-1),遗传变异系数为24.59%—32.69%,可溶性糖含量遗传率为68.14%。通过全基因组关联分析,连江春季、福清春季和秋季3个环境下分别检测到与鲜籽粒可溶性糖含量显著关联的SNP有6、8和22个,表型变异解释率为12.43%—29.27%,以表型变异解释率较高的9个显著SNP位点所在的候选区间进行搜索,共获得86个基因,结合基因注释和组织表达信息,进一步筛选到9个候选基因,主要涉及转录因子、糖蛋白家族和糖类合成转运等生物学过程。其中,Glyma.01g016500、Glyma.13g042100、Glyma.16g131800和Glyma.16g155300在大豆种子及荚中表达水平较高,可作为大豆鲜籽粒可溶性糖的最具潜力候选基因。【结论】通过全基因组关联分析,检测到36个与鲜籽粒可溶性糖含量显著关联的SNP,进一步筛选出9个候选基因可能参与大豆鲜籽粒可溶性糖含量的调控,其中,Glyma.01g016500、Glyma.13g042100、Glyma.16g131800和Glyma.16g155300可作为调控大豆鲜籽粒可溶性糖含量的关键目标基因。

黄河兰州段一株优势藻的分离鉴定及光照、pH、温度对其生长的影响

为探究黄河兰州段水域的优势绿藻,从金牛街码头和中山桥水域采集水样,分离得到4株微藻,初步鉴定为小球藻属(Chlorella)、链带藻属(Desmodesmus)、近头状尖胞藻属(Raphidocelis)和空星藻属(Coelastrum),依次命名为Chlorella sp.HH13,Desmodesmus sp.HH2C,Raphidocelis sp.HHTXZ和Coelastrum sp.HH4.4株藻培养9 d后生物量水平表现为HH13>HH2C>HHTXZ>HH4,选取HH13作为目标藻种探究其在最佳光照、pH和温度条件下的生物量、光合色素、可溶性蛋白以及可溶性糖的积累.在BG11培养基中培养HH13,确定最佳光照强度为6000 Lux,类胡萝卜素和总叶绿素含量达到最大值,分别为2.029和6.929 mg·g^(-1),可溶性糖和可溶性蛋白的含量也最高,分别为0.285%和7.661 mg·g^(-1);最佳pH值为7,生物量最高可达0.297 g·L^(-1),类胡萝卜素和总叶绿素含量达到最大值,分别为2.753和9.711 mg·g^(-1),可溶性糖和可溶性蛋白含量也最高,分别为0.484%和5.674 mg·g^(-1);最佳温度为28℃,生物量最高为0.289 g·L^(-1),类胡萝卜素和总叶绿素含量分别为1.796和6.073 mg·g^(-1),可溶性糖含量为0.288%,可溶性蛋白的含量为5.898 mg·g^(-1).最终得到HH13生长的最佳光照强度为6000 Lux、pH值为7、温度为28℃.

柱前衍生-气相色谱-质谱联用法同时测定茯苓中的可溶性糖与三萜酸

[目的]通过建立柱前衍生-气相色谱-质谱(GC-MS)法实现茯苓(Poria cocos)各成分的快速高效分离检测,为茯苓有效成分的分析提供新方法并为茯苓原料品质判断提供参考.[方法]采用超声辅助提取法,以反油酸为内标物,甲氧胺(MOX)和N-甲基-N-(三甲基硅烷)三氟乙酰胺[含1%(质量分数)三甲基氯硅烷](MSTFA+1%TMCS)为肟化-硅烷化衍生试剂,采用GC-MS同时检测茯苓中的果糖、葡萄糖、海藻糖、阿拉伯糖醇、甘露糖醇、山梨糖醇、麦芽糖醇、茯苓酸、茯苓新酸A和茯苓新酸B.[结果]优化后的衍生条件为:200μL茯苓的甲醇提取液氮气吹干后,加入50μL MOX,于40℃反应2 h,然后加入250μL(MSTFA+1%TMCS),于40℃下反应30 min.衍生后的目标化合物在40 min内完成分离分析,线性关系良好,相关系数均在0.9935以上,该方法的定量限为0.008~1.000μg/mL,检测限为0.003~0.300μg/mL.茯苓样品加标回收率为82.0%~122.4%,相对标准偏差为1.05%~4.43%.[结论]本方法样品用量少,结果稳定且灵敏度高,可用于检测茯苓样品中可溶性糖和微量的三萜酸类化合物,同时也为检测其他样品中的三萜酸类化合物提供更多的选择.

枸杞SWEET基因家族鉴定及其与可溶性糖含量关系

【目的】糖外排转运蛋白(sugars will eventually be exported transporters,SWEETs)在植物生长发育过程中发挥重要作用,解析SWEETs基因在枸杞果实发育过程中对糖积累作用,为进一步揭示SWEETs基因在枸杞果实发育过程中的作用提供参考。【方法】用生物信息学方法对枸杞SWEET基因(LbaSWEETs)进行全基因组鉴定,并用已发表的转录数据分析LbaSWEETs在果实发育时期的基因表达情况。【结果】枸杞SWEET基因家族共有37个成员,随机分布于10条染色体上,分别编码152~621个氨基酸,蛋白质分子质量为16.87~69.97 kD,等电点为4.96~9.86。亚细胞定位预测位于叶绿体或质膜,大多数含有7个跨膜螺旋。系统进化分析发现,37个LbaSWEETs蛋白可分为4个亚群,每个亚群的基因结构和保守基序组成相似。启动子元件分析表明:Lba-SWEETs基因启动子富含大量激素响应、逆境胁迫和生长发育响应元件。转录组数据和qRT-PCR分析表明:LbaSWEET9和LbaSWEET29基因表达量随果实成熟呈现显著增加。相关性分析结果表明,LbaSWEET9和LbaSWEET29基因表达量与果糖含量呈显著正相关。【结论】LbaSWEET9和LbaSWEET29基因是果糖积累的关键基因。

石蒜种子发育过程中形态及内含物的变化规律

为探究石蒜种子发育过程中的形态及内含物变化规律,更好地确定适宜的采种期,以花后7,14,21,28,35,42,49,56,63,70 d的新鲜石蒜种子为研究材料,在形态观测的基础上,结合烘干法、考马斯亮蓝G-250法和蒽酮比色法测定种子的含水量和内含物(可溶性糖、可溶性蛋白质和淀粉)含量。结果表明:石蒜的种子成熟脱落时含水量仍较高(72.47%),且生活力(83.33%)和可溶性糖(61.40 mg·g^(-1))、淀粉(35.65 mg·g^(-1))的含量均较高,而可溶性蛋白质含量极少(0.70 mg·g^(-1)),符合顽拗性种子特性。依据种子形态变化特征,可将其发育过程划分为空泡化时期(花后7~14 d)、液态化时期(花后21~28 d)、胶质化时期(花后35 d)、胚发育时期(花后42~56 d)和成熟期(花后63~70 d)共5个时期,持续时长约为70 d。在整个发育期间,种皮的颜色由初始的透白色变为褐色,最终转为黑色;胚乳内的淀粉、可溶性糖和蛋白质含量均随发育时间的延长显著上升,而含水量显著下降。其中,花后42 d是石蒜种子发育的重要节点,开始出现种胚结构,花后56~70 d时种胚发育成熟,发芽率分别为8.67%、14.33%和23.33%。结合石蒜种子在发育过程中的内、外部的形态特征变化及内含物的变化规律,确定适宜的采收期为花后63~70 d,即宜在种皮由褐色转为黑色,含水量为72.47%~74.13%时采收,此时种子已完成干物质积累且具备萌发力。