Prohexadione-calcium (Pro-Ca) has been shown to positively regulate crop tolerance to saline–alkali stress. However, the optimal concentration of Pro-Ca application and the mechanisms through which it enhances saline–alkali tolerance and yield in soybean remain unclear. This study aimed to determine the optimal concentration of exogenously applied Pro-Ca and reveal the mechanisms underlying Pro-Ca’s effect on remediation and yield response in soybean under saline–alkali stress. The results indicated that saline–alkali stress negatively impacted the morphological and physiological traits of soybean seedlings by triggering the production of reactive oxygen species (ROS), leading to oxidative damage of the grana lamellae due to excessive accumulation of Na+. An application of 100 mg L−1 Pro-Ca was found to be optimal, promoting dry matter accumulation and normalized difference vegetation index (NDVI) by significantly reducing Na+ uptake under saline–alkali stress. Moreover, integrated physiological, ultrastructural, and transcriptomic analyses indicated that Pro-Ca significantly enhanced the ascorbate–glutathione (AsA–GSH) cycle by up-regulating the expression of related genes to enhance the activities of ascorbate peroxidase (APX), glutathione reductase (GR), dehydroascorbate reductase (DHAR), monodehydroascorbate reductase (MDHAR), and the AsA/dehydroascorbate (DHA) and GSH/oxidized glutathione (GSSG) ratios to quench ROS, thereby protecting both thylakoid and mitochondrial membranes from degradation. The differentially expressed genes (DEGs) encoding ascorbate and aldarate metabolism were significantly (P<0.05) enriched in the integral component of the membranes. Furthermore, Pro-Ca treatment up-regulated the expression of genes encoding photosystems under saline–alkali stress, thereby reducing the photoinhibition and stomatal limitation (Ls), mitigating damage to photosystems, and preventing yield reduction. In summary, foliar application of Pro-Ca could efficiently enhance soybean seedlings’ tolerance to saline–alkali stress by inhibiting Na+ influx, enhancing the AsA–GSH cycle, maintaining the biomembrane system, and improving photosynthetic efficiency.

The aim of this study was to determine the mechanism by which exogenous choline chloride (CC) improves the strength of rice seedlings under salt stress and to evaluate the correlation between the seedling index (SI) and rice yield. To this end, the effects of foliar spraying of 500 mg L−1 CC at the three-leaf stage on the salt tolerance, yield, and yield components of the salt-tolerant rice Wanshengyou Tianhong 4 (WSY) and the salt-sensitive rice Huanghuazhan (HHZ) were investigated. CC application remarkedly increased the SI of WSY and HHZ under NaCl stress compared with NaCl treatment, and this was positively correlated with the rice yield. These phenomena were more pronounced when CC was applied to HHZ under NaCl stress as an exogenous spray. The CC application also enhanced the ROS scavenging ability by upregulating antioxidant enzyme activities, enhancing the ascorbate-glutathione (AsA-GSH) cycle, inhibiting Na+ uptake, and promoting osmotic solute accumulation. Meanwhile, CC increased the levels of indole-3-acetic acid (IAA), salicylic acid (SA), and zeatin (ZT) and decreased the abscisic acid (ABA) level in HHZ under NaCl stress. Furthermore, the exogenous application of CC notably increased the yield of NaCl-stressed WSY by 11.17

IntroductionSalt stress is a major abiotic stress that affects crop growth and productivity. Choline Chloride (CC) has been shown to enhance salt tolerance in various crops, but the underlying molecular mechanisms in rice remain unclear.MethodsTo investigate the regulatory mechanism of CC-mediated salt tolerance in rice, we conducted morpho-physiological, metabolomic, and transcriptomic analyses on two rice varieties (WSY, salt-tolerant, and HHZ, salt-sensitive) treated with 500 mg·L-1 CC under 0.3% NaCl stress.ResultsOur results showed that foliar application of CC improved morpho-physiological parameters such as root traits, seedling height, seedling strength index, seedling fullness, leaf area, photosynthetic parameters, photosynthetic pigments, starch, and fructose content under salt stress, while decreasing soluble sugar, sucrose, and sucrose phosphate synthase levels. Transcriptomic analysis revealed that CC regulation combined with salt treatment induced changes in the expression of genes related to starch and sucrose metabolism, the citric acid cycle, carbon sequestration in photosynthetic organs, carbon metabolism, and photosynthetic antenna proteins in both rice varieties. Metabolomic analysis further supported these findings, indicating that photosynthesis, carbon metabolism, and carbon fixation pathways were crucial in CC-mediated salt tolerance.DiscussionThe combined transcriptomic and metabolomic data suggest that CC treatment enhances rice salt tolerance by activating distinct transcriptional cascades and phytohormone signaling, along with multiple antioxidants and unique metabolic pathways. These findings provide a basis for further understanding the mechanisms of metabolite synthesis and gene regulation induced by CC in rice in response to salt stress, and may inform strategies for improving crop resilience to salt stress.

为探讨种子引发剂对盐胁迫下水稻幼苗生长及生理特性的影响机制,以杂交稻湘两优900和常规稻黄华占为材料,研究引发剂氯化胆碱(CC)和吲哚丁酸钾(IBAK)对盐胁迫下水稻幼苗生长、光合特性、抗氧化代谢及渗透调节的影响.结果表明,盐胁迫抑制水稻幼苗生长,3.0mg·L-1CC和1.0mg·L-1 IBAK为缓解盐胁迫对水稻幼苗生长抑制的适宜引发浓度,添加引发剂CC的湘两优900根干重显著增加9.64％,而添加引发剂CC和IBAK的黄华占根系总长度、叶面积、地上干重、根干重、壮苗指数分别显著增加 24.78％和 14.39％、43.06％和 36.33％、11.45％和 7.43％、34.60％和 28.62％、41.89％和33.55％.引发剂CC和IBAK处理可显著提高盐胁迫下两品种水稻叶片的净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和叶绿素含量;激活超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性;同时增加抗坏血酸(AsA)、谷胱甘肽(GSH)、可溶性蛋白和脯氨酸含量;抑制活性氧积累,降低丙二醛(MDA)含量和相对电导率(REC)水平.盐和引发剂处理在两品种水稻抗氧化指标间均存在普遍的交互作用,而形态指标或光合参数间的交互作用在黄华占中更为显著.综上所述,引发剂CC和IBAK主要通过增强抗氧化系统活性、提高渗透调节潜力、降低活性氧损伤来提高水稻幼苗的耐盐性.本研究结果为探明引发剂缓解水稻盐胁迫损伤的作用机理提供了理论依据.

Prohexadione-calcium (Pro-Ca) has been proved to play an important role in releasing abiotic stress in plants. However, there is still a lack of research on the mechanism of Pro-Ca alleviating salt stress in rice. To explore the protective effects of Pro-Ca on rice seedlings under salt stress, we investigated the effect of exogenous Pro-Ca on rice seedling under salt stress by conducting the following three treatment experiments: CK (control), S (50 mmol·L −1 NaCl saline solution) and S + Pro-Ca (50 mmol·L −1 NaCl saline solution + 100 mg·L −1 Pro-Ca). The results indicated that Pro-Ca modulated the expression of antioxidant enzyme-related genes (such as SOD2 , PXMP2 , MPV17 , E1 . 11 . 1 . 7 ). Spraying Pro-Ca under salt stress significantly increased in ascorbate peroxidase, superoxide dismutase, and peroxidase activity by 84.2%, 75.2%, and 3.5% as compared to the salt treatment, as demonstrated by an example of a 24-hour treatment. Malondialdehyde level in Pro-Ca was also dramatically decreased by 5.8%. Moreover, spraying Pro-Ca under salt stress regulated the expression of photosynthesis genes (such as PsbS , PsbD ) and chlorophyll metabolism genes ( heml , PPD ). Compared to salt stress treatment, spraying Pro-Ca under salt stress significantly increased in net photosynthetic rate by 167.2%. In addition, when rice shoots were sprayed with Pro-Ca under salt stress, the Na + concentration was considerably reduced by 17.1% compared to salt treatment. In conclusion, Pro-Ca regulates antioxidant mechanisms and photosynthesis to aid in the growth of rice seedlings under salt stress.

To investigate the alleviating effects of spraying Nengbaiwang 2.0（0.16% 14-hydroxylated brassinosteroid·thidiazuron+polyglutamic acid） at different stages on rice growth and yield under salt stress, hybrid rice ‘Xiangliangyou 900’ and commonly cultivated rice ‘Huanghuazhan’ were used as the experimental materials to examine the effects of continuous spraying Nengbaiwang for 2（sprayed once at tillering stage and heading stage） or 3（sprayed once at tillering stage, heading stage, and grain filling stage） times on photosynthetic characteristics, antioxidant metabolism, osmotic regulation, and yield of rice under 0.3% salt stress. The results showed that salt stress inhibited the growth of both rice varieties, significantly decreased net photosynthetic rate（P n ）, and reduced yield by 33.7% and 43.2% in Xiangliangyou 900 and Huanghuazhan, respectively. Foliar spraying Nengbaiwang could alleviate the negative effects of salt stress on rice growth. Spraying Nengbaiwang twice significantly increased the effective tillers of Xiangliangyou 900 and Huanghuazhan, and spraying three times significantly increased plant height, stem diameter, total leaf number, flag leaf length, and inverted second leaf length of Huanghuazhan under salt stress compared with the single salt treatment. Foliar spraying Nengbaiwang for two or three times significantly increased the P n , stomatal conductance（G s ）, chlorophyll content, the activities of antioxidant enzymes（SOD, CAT, POD, and APX）, the levels of non-antioxidants（AsA and GSH）, and proline accumulation. However, it decreased the contents of hydrogen peroxide（H 2 O 2 ） and malondialdehyde（MDA） under salt stress compared to the single salt treatment. The yield loss of Xiangliangyou 900 and Huanghuazhan was alleviated by 20.0% and 14.3%, respectively, after spraying twice Nengbaiwang, and 14.5% and 28.6%, respectively, after spraying three times Nengbaiwang. In conclusion, foliar spraying Nengbaiwang could reduce the damage caused by salt stress on rice by enhancing photosynthetic activity, antioxidant system, and osmotic regulation potential, thus alleviating yield loss under salt stress.

To monitor the role of exogenous uniconazole in mitigating chilling stress, this study investigated the effect of foliar spraying of 50 mg L-1 uniconazole on the chilling (15 degrees C) tolerance of mung beans at the flowering stage. The results showed that uniconazole significantly enhanced the reactive oxygen species (ROS) scavenging ability of mung beans by increasing the superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), glutathione reductase (GR) activities, the contents of ascorbic acid (AsA) and glutathione (GSH), and the tran-scription levels of SOD and POD under chilling stress. The uniconazole applications also drastically increased the net photosynthetic rate (P-n), maximum net photosynthetic rate (P(n)max), maximum quantum yield of PSII (F-v/ F-m), and the expression levels of the corresponding photosynthetic genes PsbO, PsbP, PsbQ, PsbY, and Psb28. This, in turn, resulted in a higher sucrose content. Meanwhile, uniconazole increased the indole-3-acetic acid (IAA) content but reduced the gibberellin A3 (GA(3)) content under chilling stress. During the recovery period, the photosynthetic parameters and ROS of plants receiving uniconazole recovered faster, and the antioxidant activity and non-antioxidant contents were higher than in chilling-treated plants. Additionally, chilling stress markedly reduced the pod number per plant, grain number per plant, and 100-seed weight, whereas uniconazole signif-icantly increased the grain weight per plant by 53.47% compared to the chilling treatment. These results strongly suggest that uniconazole can effectively protect mung beans from chilling stress damage by protecting the photosynthetic machinery and enhancing the antioxidant capacity to quench excessive ROS caused by chilling stress. These effects are closely relevant to chilling tolerance enhancement and yield improvement in mung beans.

为明确外源调环酸钙(Pro-Ca)缓解大豆幼苗盐碱胁迫的机理,以大豆'合丰50'为试验材料,研究在110 mmol·L-1复合盐碱胁迫下,叶面喷施100 mg·L-1 Pro-Ca对大豆幼苗生长、光合特性、抗氧化代谢、AsA-GSH循环以及渗透调节的影响.结果表明:盐碱胁迫显著抑制大豆幼苗生长,降低了净光合速率(Pn)、叶绿素、可溶性蛋白、可溶性糖、蔗糖和淀粉含量;增加了过氧化氢酶(CAT)活性以及脯氨酸、活性氧(ROS)、丙二醛(MDA)和电解质渗漏率积累;与盐碱处理相比,喷施Pro-Ca能够改善大豆幼苗地上部和根系生长,提高叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量,维持较高的Pn,促进蔗糖、果糖和淀粉的积累;显著上调叶片6种抗氧化酶(SOD、POD、CAT、GR、MDHAR和DHAR)活性、2种非酶抗氧化剂(AsA和GSH)水平和脯氨酸含量;而电解质渗漏率、O2·-产生速率以及MDA和H2O2含量显著降低.综上所述,调环酸钙通过调节抗氧化酶活性和AsA-GSH循环系统、增加渗透溶质积累、降低ROS损伤来提高大豆幼苗对盐碱胁迫的耐性.

[目的]探讨不同微生物菌剂对水稻幼苗形态建成及生理特性的调控效应,丰富微生物菌剂在调节水稻生长方面的应用研究,同时为水稻的优质高效栽培提供理论依据.[方法]以常规稻海红12为试验材料,采用盆栽试验,于水稻1叶1心期分别浇灌100 mL浓度均为1％的5种微生物菌剂[短小芽孢杆菌(BP)、红酵母与酿酒酵母混合液(RS)、枯草芽孢杆菌(BS)、纳豆芽孢杆菌(BN)、解淀粉芽孢杆菌(BA)],以浇灌100 mL清水为对照(CK).于水稻4叶期取样,对比分析不同微生物菌剂对1叶1心期水稻幼苗灌根后形态特征、超氧阴离子(O-2·)产生速率、抗氧化酶活性、丙二醛(MDA)和可溶性蛋白含量的影响.[结果]与CK相比,5种外源菌剂均能促进海红12幼苗生长,显著增加株高、地上部干重、根表面积和根体积(P<0.05,下同),增长率分别为4.9％～18.4％、23.3％～44.2％、44.5％～86.6％和75.0％～175.0％,其中以BN处理效果较佳;BS和BA处理对增加叶片SPAD值的效果较好,但各菌剂处理与CK无显著差异(P>0.05);BP、BS、BN和BA处理均能不同程度地提高水稻叶片的可溶性蛋白含量及超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,增长率分别为5.6％～17.8％、61.1％～126.7％、66.1％～117.9％,BP、BS和BN处理的过氧化氢酶酶(CAT)活性分别显著提高17.6％、29.7％、21.6％;BN处理的抗坏血酸过氧化物酶(APX)活性显著提高112.8％,其中BS和BN处理调控效较优;BP、BN和BA处理显著降低叶片MDA含量11.8％～16.6％,O-2·产生速率在BP和BN处理后显著降低53.2％和42.9％.[结论]微生物菌剂通过增加株高、地上干重、根表面积和根体积显著促进海红12幼苗形态建成,通过提高抗氧化酶活性、降低膜脂过氧化程度、提高可溶性蛋白积累来增强水稻幼苗的代谢水平与抗逆能力.5种菌剂中以纳豆芽孢杆菌的综合调控效果较优.

以绿豆'绿丰5号'为材料,研究15℃低温胁迫下叶面喷施50 mg·L-1烯效唑(S3307)对初花期叶片碳代谢、抗氧化酶活性及产量的影响.结果表明:外源喷施S3307能够显著增强低温胁迫下叶片过氧化物酶(POD)、抗坏血酸过氧化物酶(APX)、谷胱甘肽还原酶(GR)、蔗糖磷酸合成酶(SPS)和α-淀粉酶活性,同时降低过氧化氢酶(CAT)和蔗糖合成酶(SS)活性,而对超氧化物歧化酶(SOD)、中性转化酶(NI)和酸性转化酶(AI)活性影响不显著;促进可溶性糖、蔗糖和淀粉积累,降低果糖含量;抑制丙二醛(MDA)含量增加,显著降低相对电导率(REC)、过氧化氢(H2O2)水平和超氧阴离子(O2·-)产生速率.此外,叶面喷施S3307对低温胁迫下的产量损失具缓解作用,但差异不显著.综上所述,外源喷施S3307通过提高叶片碳代谢能力和抗氧化系统活性,减轻了低温对绿豆造成的伤害,从而在一定程度上缓解了低温胁迫下的产量损失.

为探讨调环酸钙(Pro-Ca)对盐碱胁迫下大豆(Glycine max)根系生长的缓解作用,以大豆品种合丰50(耐盐)和垦丰16(盐敏感)为试验材料,研究叶面喷施100 mg·L-1 Pro-Ca对盐碱胁迫下大豆根系生长特性、活性氧代谢、抗氧化酶活性和渗透调节物质含量的影响.结果表明,外源喷施Pro-Ca均能不同程度缓解盐碱胁迫对合丰50和垦丰16根系生长的抑制,两品种根长、根鲜重和根干重分别增加了11.2％和23.6％、3.2％和19.8％、38.0％和37.6％;上调了盐碱胁迫下大豆根系超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性以及抗坏血酸(AsA)和谷胱甘肽(GSH)水平;抑制了 O2·-和H2O2积累,降低了丙二醛(MDA)含量和电解质渗漏率(EL);促进了渗透调节物质积累,合丰50和垦丰16大豆根系的可溶性糖、可溶性蛋白和脯氨酸含量分别增加了 5.1％～7.8％和6.2％～28.0％、6.6％～17.8％和3.8％～10.3％、19.1％～31.9％和6.9％～27.8％.主成分分析表明外源喷施Pro-Ca对耐盐品种合丰50和盐敏感品种垦丰16根系均具有较好的调控效果.综上所述,外源喷施Pro-Ca可通过增强根系抗氧酶活性、渗透调节能力以及降低膜脂过氧化来增强大豆根系的耐盐碱能力.本研究初步阐明了 Pro-Ca缓解大豆根系盐碱胁迫伤害的生理生化机制,为进一步从分子水平揭示其作用机制提供了理论依据.

Soil salinization seriously restricts the growth and yield of soybeans. However, little information is available on the early growth stages of soybeans which are subjected to the gibberellin biosynthesis inhibitor, prohexadione-calcium (Pro-Ca). This study aimed to investigate the effects of exogenous Pro-Ca on saline-alkali stress-induced damages to photosynthesis and antioxidant defenses in soybean (Glycine max L.) seedlings. At the V3 growth stage, salt-tolerant genotype Hefeng 50 (HF50) and salt-sensitive genotype Kenfeng 16 (KF16) were subjected to 110 mmol L−1 mixed saline-alkali stress respectively, and then 100 mg L−1 Pro-Ca was sprayed on the leaves. Our results showed that saline-alkali stress accelerated the degradation of thylakoids, inhibited chlorophyll synthesis, reduced shoot dry weight, electron transfer rate (ETR), and peroxidase (POD) activity, the concentration of ascorbic acid (AsA) and soluble sugar, but enhanced the concentration of proline, hydrogen peroxide (H2O2) and the rate of superoxide radical (O2∙−) generation. Additionally, saline-alkali stress induced a lower decrease of the net photosynthetic rate (Pn), potential activity of PSII (Fv/F0), and maximum quantum yield of PSII (Fv/Fm) in salt-tolerant HF50 than in salt-sensitive KF16. Nevertheless, foliar spraying of exogenous Pro-Ca increased the chlorophyll content, Pn, Fv/F0, and Fv/Fm. These results were more prominent when Pro-Ca was applied to KF16 under saline-alkali conditions. Furthermore, exogenous application of Pro-Ca retarded the degradation of thylakoids, increased the ETR and the accumulation of AsA, soluble sugar, and proline, activated the activities of superoxide dismutase (SOD), catalase (CAT), and POD, and decreased the concentration of malondialdehyde (MDA), electrolyte leakage (EL), O2∙−, and H2O2. These results indicated that Pro-Ca could effectively protect soybean seedlings against damage from saline-alkali stress by regulating seedling phenotype, photosynthetic apparatus, antioxidant defense, and osmoregulation.

Soil salinization has become a global problem and seriously endangers crop growth and yield improvement. In the present study, soybean (Hefeng 50) seedlings were used as test materials to study the mitigation effect of foliar spraying of different plant growth regulators (PGRs) [50 mg L−1 indole-3-butyric acid potassium salt (IBAK), 50 mg L−1 chitosan oligosaccharide (COS), 2 mg L−1 abscisic acid (ABA), 30 mg L−1 5-aminolevulinic acid (ALA), and 1.2 mg L−1 brassinolide (BR)] on oxidative stress caused by the mixed Saline–Alkali concentration of 110 mmol L−1. The results showed that the application of PGRs promoted the growth of Saline–Alkali stressed plants, where the maximum increase in shoot FW was treated with COS, and in root FW, root length, root surface area, and root volume were obtained with the IBAK treatment. Treatments ABA, ALA, and BR had higher net photosynthetic rates, and the chlorophyll content was considerably increased under COS and BR treatments compared with Saline–Alkali treatment. Moreover, PGRs markedly enhanced the activities of antioxidant enzymes, the concentration of ascorbate (AsA), glutathione (GSH), proline, soluble protein, soluble sugar, sucrose, and starch, and the ratios of AsA/DHA and GSH/GSSG, but reduced the concentration of malondialdehyde (MDA), electrolyte leakage (EL), hydrogen peroxide (H2O2), and superoxide radical (O2·−) in soybean seedlings compared with Saline–Alkali treatment. The principal component analysis revealed that the ranking of PGRs enhancing Saline–Alkali tolerance of soybean seedlings was BR > IBAK > ABA > COS > ALA, and the most effective treatment was BR, which may be assigned to more vigorous antioxidant defense and osmotic adjustment.

[目的]探究不同植物生长调节剂拌种对玉米幼苗生长、光合荧光特性及产量的影响,为化控技术在玉米生产上的应用和高产高效栽培提供理论依据.[方法]以德美亚1号和先达101为供试玉米品种,采用田间随机区组试验,设置4种调节剂[海藻酸钠寡糖(AOS)、1-(2,4-二氯甲酰氨基环丙羧酸,B2)、冠菌素(COR)和抗光解S-ABA(ABA)]拌种处理,以不添加调节剂拌种处理为CK,研究不同植物生长调节剂对玉米幼苗形态建成、生物量积累、光合特性、叶绿素荧光特性及产量的调控效应.[结果]与CK相比,AOS、B2、COR和ABA处理均对德美亚1号和先达101幼苗生长有促进作用,均能增加茎粗,促进地上生物量和地下生物量积累.AOS、B2和ABA处理提高了德美亚1号和先达101的叶面积.COR和ABA处理下,德美亚1号的根冠比均高于CK.B2和COR处理下,先达101的根冠比均高于CK.B2和COR处理下,德美亚1号和先达101的叶绿素含量、Pn、Gs、Tr、Y(Ⅱ)、ETR和(Fv/Fm)均显著高于CK.各处理显著增加了德美亚1号和先达101的穗粒数和千粒重,AOS、B2、COR和ABA处理的德美亚1号和先达101产量分别较CK增加4.79％、12.38％、14.79％、13.38％和6.61％、8.40％、7.35％、4.45％.[结论]植物生长调节剂AOS、B2、COR和ABA拌种处理可以促进幼苗生长,提高叶片光合荧光性能,促进生物量的积累,有利于培育壮苗,提高玉米产量.其中,COR处理对德美亚1号产量的调控效果较好,B2处理对先达101产量的调控效果较好.

为探讨调环酸钙(prohexadione-calcium,Pro-Ca)对盐胁迫下水稻幼苗的缓解作用,明确Pro-Ca提高水稻耐盐能力的最适浓度,以水稻品种'黄华占'为试验材料,研究不同浓度(25、50、75、100、125、150 mg·L-1)Pro-Ca对盐胁迫下水稻幼苗生长及抗性生理的影响.结果表明:盐胁迫抑制水稻正常生长,对水稻抗性生理产生不利影响.外源添加Pro-Ca促进盐胁迫下水稻幼苗的地上部生长,提高根系活力,增强超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,提高可溶性蛋白和脯氨酸的含量,降低叶片相对电导率及O2-的产生速率,增加叶片SPAD,提高净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)、胞间CO2浓度(Ci)和表观叶肉导度(AMC).综合分析,100 mg·L-1浓度处理时效果最好,表现为茎基宽、根系总长度、干质量、净光合速率及CAT等出现最大值.初步推断在盐胁迫下,Pro-Ca通过提高植物抗氧化酶活性、叶绿素含量及渗透调节物质含量,降低幼苗O-2的产生速率及电解质渗透来保护细胞结构的完整,促进幼苗生长及光合速率的上升,从而增强水稻幼苗耐盐能力.

为探究壳聚糖拌种和叶面喷施对玉米光合特性及产量的影响、明确壳聚糖拌种和叶面喷施的适宜剂量,以玉米德美亚1号为材料,采用田间随机区组试验方法,设置壳聚糖拌种剂量0(CK)、25(B-CTS1)、50(B-CTS2)、100(B-CTS3)mg/kg和在6展叶期叶面喷施剂量0(CK)、25(Y-CTS1)、50(Y-CTS2)、100(Y-CTS3)mg/L.结果表明:与CK相比,壳聚糖拌种和叶面喷施处理能增加玉米叶面积,提高玉米叶片SPAD值、净光合速率(Pn)、蒸腾速率(Tr)、气孔导度(Gs)和胞间CO2浓度(Ci),增加干物质积累量;壳聚糖拌种和叶面喷施处理产量较CK分别增加8.2％、14.1％、12.4％和8.0％、12.3％、10.1％.综上所述,壳聚糖拌种剂量在50mg/kg时、叶面喷施剂量在50mg/L时,增产效果较好.

为探讨新型植物生长调节剂B2拌种和叶面喷施对玉米农艺性状、光合特性、叶绿素荧光参数及产量的影响,明确B2拌种和叶面喷施的适宜剂量,以德美亚1号为材料,采用田间随机区组试验方法,设置B2拌种剂量0 (CK)、25(BT1)、50(BT2)和100(BT3) mg/kg,在6展叶期叶面喷施剂量0(CK1)、25(YT1)、50(YT2)和100(YT3) mg/L.结果 表明:与CK和CK1相比,B2拌种和叶面喷施处理均能降低玉米株高和穗位高,增加玉米茎粗、叶面积和干物质积累量;提高玉米叶片SPAD值、净光合速率(Pn)和蒸腾速率(Tr);提高实际量子产量Y(Ⅱ)、相对电子传递效率(ETR)、最大光化学效率(Fv/Fm)和潜在光化学活性(Fv/F0),降低非光化学猝灭系数(NPQ);B2拌种和叶面喷施处理产量较CK和CK1分别增加5.90％、14.20％、5.81％和11.72％、14.40％、5.36％.综上所述,B2拌种剂量为50mg/kg、叶面喷施剂量为50mg/L时,可显著增加玉米产量.

以大豆垦丰14为材料,利用Planteye F500三维扫描仪定量研究烯效唑对淹水胁迫下大豆生长的影响,建立三维表型参数与形态生理指标之间的相关性.结果表明:淹水处理降低了大豆株高、数字生物量、叶片倾斜度、植株3D叶面积、投影叶面积和光穿透深度等形态指标,分别较对照下降20.51％、45.25％、15.60％、31.22％、18.67％和26.59％.喷施烯效唑降低了淹水处理下大豆数字生物量、株高、3D叶面积、投影叶面积以及光穿透深度,并较淹水处理低22.50％、19.25％、5.94％、14.80％和56.12％.大豆植株实际叶面积、3D叶面积、投影叶面积三者呈正相关关系.通过部分生理指标相关性分析发现,SPAD值与归一化植被指数NDVI呈正相关,与色调值、光穿透深度呈负相关.相关性分析结果为表型组学与作物栽培学的结合提供了依据.

探讨外源调环酸钙(EA)对复合盐碱胁迫下大豆的缓解作用,明确EA提高大豆耐盐碱能力的适宜浓度,以大豆品种合丰50和垦丰16为试验试材,分别在110 mmol·L-1的复合盐碱胁迫下培养15 d取样,研究V3期叶面喷施不同浓度EA(5～200 mg·L-1)对大豆光合特性和保护酶活性的影响.结果表明:与对照相比,各浓度EA处理均能增加盐碱胁迫下两品种大豆叶片叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量,降低Chl a/b的比值;提高大豆叶片Pn、Gs、Tr、Ls、WUE和AMC,降低了Ci;显著提升大豆叶片SOD、POD、CAT活性,抑制了MAD含量的增加.综合分析表明,100 mg·L-1浓度处理时效果最好,表现为叶绿素指标、净光合速率和抗氧化酶活性随EA浓度的增加呈现先上升后下降的趋势,在100 mg·L-1出现最大值.初步推断在盐碱胁迫下,施加的外源EA通过提高植物抗氧化酶活性和叶绿素含量、降低MDA含量来保护细胞结构的完整、阻止光合速率的下降,促进幼苗生长,从而增强大豆幼苗耐盐碱胁迫的能力,100 mg·L-1处理时效果最佳.

为明确新型植物生长调节剂CGR3-1对绿豆生长的影响,以绿豆品种绿丰2号和绿丰5号为材料,对比研究了三节期(V3)和始花期(R1)喷施100 mg/L植物生长调节剂CGR3-1[1-(3,3-二甲基-2-氧代丁基)-1H-1,2,4-三氮唑-3-羧酸]对绿豆叶片光合气体交换参数、碳同化产物、产量及籽粒脂肪酸组成的影响.结果表明,V3期喷施CGR3-1对鼓粒盛期绿豆叶片光合气体交换参数无明显影响,R1期喷施则使鼓粒盛期绿丰2号叶片净光合速率较蒸馏水处理(CK)显著降低27.10％.光合碳同化产物结果表明,V3期喷施CGR3-1使绿丰2号始花期叶片蔗糖、淀粉含量分别较CK显著增加54.68％、62.10％,使绿丰5号鼓粒盛期叶片蔗糖含量显著降低,淀粉含量极显著提高;R1期喷施CGR3-1对鼓粒盛期绿豆叶片蔗糖含量无显著影响,但使绿丰2号和绿丰5号叶片淀粉含量分别较CK极显著降低22.00％和15.53％.V3期喷施CGR3-1降低籽粒百粒质量,而R1期喷施则增加百粒质量.V3期喷施CGR3-1提高了绿豆单株荚数、单株粒数,从而提高绿豆产量.喷施CGR3-1改变了绿豆籽粒的脂肪酸组成,V3期喷施CGR3-1有利于亚油酸含量的提高.整体而言,V3期喷施植物生长调节剂CGR3-1可有效提高绿豆单株产量,改善品质.