不同胁迫对新疆大叶补血草种子萌发的影响

以分布在新疆北疆境内的大叶补血草为材料,通过模拟野外3种不同胁迫环境(即0~300 mmol/L NaCl溶液、0~150 mmol/L Na_(2)CO_(3)溶液、0~595 mmol/L甘露醇溶液)对种子萌发生理的影响。结果表明,随NaCl浓度增加,种子萌发时间推迟,发芽指数先增加后减少,在50 mmol/L NaCl时最大;随NaCl处理时间的延长,种子发芽势升高,萌发率曲线呈上升趋势并趋于稳定,且在300 mmol/L NaCl处理时,种子萌发率最低;随Na_(2)CO_(3)浓度增加,发芽指数先增加后减少,50 mmol/L Na_(2)CO_(3)处理下最高;随Na_(2)CO_(3)处理时间的延长,种子发芽势增加,且在第10天和第15天保持不变,萌发率曲线呈上升趋势并趋于稳定,30 mmol/L和50 mmol/L Na_(2)CO_(3)处理下,种子萌发率明显高于对照,150 mmol/L Na_(2)CO_(3)处理时,种子萌发率最低;随甘露醇浓度增加,种子萌发时间推迟,发芽指数逐渐降低,在595 mmol/L浓度处理下,种子全程无萌发,与对照相比,Na_(2)CO_(3)和甘露醇胁迫对种子胚根和子叶的生长均有抑制作用,NaCl胁迫对种子子叶生长的抑制作用高于对种子胚根生长的抑制作用;3种不同胁迫处理下,种子SOD活性变化曲线呈“V”型,POD活性变化曲线呈倒“V”型,MDA含量与溶液浓度基本呈正相关关系。研究发现,低浓度的盐胁迫、碱胁迫和渗透胁迫均促进大叶补血草种子的萌发,种子通过调节SOD、POD活性和自身生长,对3种胁迫具有一定的适应能力。

低温胁迫对4个草莓品种生理指标的影响

为探讨不同草莓品种在低温胁迫下的生理变化规律和抗寒能力,2018年以4个草莓品种为实验材料,测定了低温胁迫下叶片相对电导率(REC)、可溶性蛋白(WSP)含量、脯氨酸(Pro)含量、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性等生理指标。结果表明,随着胁迫温度下降,草莓叶片相对电导率上升、保护性物质可溶性蛋白、丙二醛、脯氨酸等含量升高;保护性酶SOD活性降低。根据相对电导率计算半致死温度,不同草莓品种抗寒性能排序为:赛娃>四公主>宁玉>粉佳人。叶片在低温胁迫过程中细胞膜质过氧化加剧,丙二醛累积,电解质外渗,脯氨酸、可溶性蛋白等渗透调节物质在胁迫的不同阶段起到不同程度的保护作用。

Effects of Low Temperature Stress on Physiological and Biochemical Characteristics of Podocarpus nagi

[Objective] The paper was to study the effect of low temperature stress on physiological and biochemical characteristics of Podocarpus nagi. [Method] Through the determination of physiological indices such as plasma membrane permeability, free proline content, soluble sugar content, malondialdehyde （MDA） content and chlorophyll content, the change law of these indices of P. nagi seedlings under natural conditions and artificially controlled low temperature conditions within the continuous 5 d was studied. [Result] The soluble sugar content, free proline content, MDA content and plasma membrane permeability of P. nagi seedlings were slightly in- creased compared with control; the chlorophyll content gradually decreased with the prolongation of low temperature stress. P. nagi seedlings produced active response to low temperature stress, so the low temperature injury P. nagi seedlings suffered was reduced. [Conclusion] The study provided theoretical basis for winter management in P. nagi cultivation in Hanjiang plain area.

Effect of Cold Stress on Some Physiological Indexes of Plants in Malvaceae

The paper was to study the change trend of the physiological indexes in plants of Malvaceae under normal and low temperature condition.The result showed that the increase extent of electrical conductivity of plants with cold tolerance in Malvaceae was significantly lower than the plant without cold tolerance under the cold stress condition,while their proline contents and soluble protein contents were all higher than the plants without cold tolerance.The above physiological indicators all can be used for the screening of varieties with cold tolerance in Malvaceae,which will also provide theoretical guidance for the cold tolerance screening of other garden plants.

Research Progress of Heat-tolerance of Brassica campestris ssp. Chinensis

Brassica campestris ssp. chinensis, also known as non-heading Chinese cabbage, is an important vegetable widely distributed in southern China. High temperature is the most common adversity factor in vegetable production, because Brassica campestris ssp. chinensis is a thermophilic vegetable, which can＇t well grow at high temperature. In summer and autumn, high temperature stress would prevent Brassica campestris ssp. chinensis from growing and result in poor quality of its seedlings, seriously influencing yield and quality of the vegetable in later period. In this paper, present situation and latest advances in heat resistance research of Brassica campestris ssp. chinensis in recent years were reviewed at home and abroad. The research tendency in Bassica campestris ssp. chinensis was also described, providing reference for breeding of heat-resistant Brassica campestris ssp. chinensis.

Effects of Exogenous Vc on Seed Germination and Physiological Properties of Oil Sunflower(Helianthus annuus) under Salt Stress

[Objective] This study aimed to provide the theoretical and technical basis for alleviating salt damages in production practice of oil sunflower （Helianthus annuus）. [Method] Seeds of oil sunflower were used as experimental materials and treated with 120 mmol/L NaCI solution and 0-200 mg/L Vc solution during the germina- tion process, to investigate the effects of exogenous Vc on seed germination and physiological properties of oil sunflower under salt stress. [Result] Under salt stress, with the increase of Vc concentration, germination potential and germination rate of oil sunflower seeds, superoxide dismutase （SOD） and peroxidase （POD） activities and proline （Pro） content of oil sunflower seedlings increased first and then declined, which reached the maixmum in 80 mg/L Vc treatment, 120 mg/L Vc treatment and 80 mg/L Vc treatment, respectively; malondialdehyde （MDA） content of oil sunflower seedlings declined first and then increased, which reached the minimum in 160 mg/L Vc treatment. [Conclusion] To varying degrees, Vc could improve germination potential and germination rate of oil sunflower seeds and promote seedling growth under salt stress, thus alleviating the damages of salt stress to seed germination and seedling growth of oil sunflower.

Preliminary Study on the Adaptability of Cucumis hystrix Chakr. under Aluminum Salt Stress

[Objective] The study was carried out to research the adaptability of Cucumis hystrix Chakr.under aluminum salt stress.[Method] Using Cucumis hystrix Chakr.and three cultivated cucumbers as tested materials,the change of physiological indexes including POD activity,SOD activity,electrolyte leakage and the content of malondialdehyde（MDA）,proline（Pro）content and soluble sugar were studied.[Result] The POD activity,SOD activity,proline content and soluble sugar content of Cucumis hystrix were higher than these of cultivated cucumbers,while electrolyte leakage and MDA content were lower,and it showed that Cucumis hystrix had better adaptability under aluminum salt stress.[Conclusion] Our study could lay a foundation for the improvement of cultivated cucumber by using the excellent characteristics of Cucumis hystrix.

我国黄秋葵栽培技术研究进展及展望

本文分别从栽培措施、干旱胁迫生理指标、栽培模式和品种比较等方面阐述和归纳了相关学者对黄秋葵的研究成果,并对黄秋葵发展前景进行了展望,以期为农业生产和进一步深入研究提供支撑和便利。

Effects of Pyrene Stress on Growth and Physiological Indexes of Maize(Zea mays L.) Seedling

[Objective]The paper was to explore the effects of pyrene stress on growth and physiological indexes of maize seedling.[Method] The effects of different concentrations of pyrene（0,0.5,1.0,and 2.0 mg/L） on growth and several physiological indexes,such as chlorophyll content,malnodiadehyde（MDA） content of both leaves and roots of maize（Zea Mays L.） seedlings of Shixiang 1（sensitive variety） and Guangtian 3（tolerant variety） were studied by a hydroponic experiment.[Result]As the concentration of prene increasing within the test concentration range,the contents of chlorophyll a and chlorophyll b in Shixiang 1 first increased and then decreased;relative growth yield and absolute growth rate showed the decreasing trend;MDA contents in roots and leaves showed the increasing trend.Relative growth yield,absolute growth rate and chlorophyll a content in Guangtian 3 first increased and then decreased;chlorophyll b and MDA contents in roots showed the increasing trend;MDA contents in leaves showed the decreasing trend.Compared with control,chlorophyll a and chlorophyll b contents of Shixiang 1 significantly increased under pyrene concentration of 0.5-1.0 mg/L,which significantly decreased as the concentration of pyrene ≥2.0 mg/L;MDA contents in roots and leaves significantly increased as the concentration of pyrene ≥1.0 mg/L,while relative growth yield and absolute growth rate significantly decreased.Chlorophyll a and chlorophyll b contents in Guangtian 3 significantly increased as the concentration of pyrene ≥1.0 mg/L.Pyrene concentration had significantly negative correlation with relative growth yield and absolute growth rate of Shixiang 1,while it had significant positive correlation with MDA contents in roots.Pyrene concentration had significant positive correlation with chlorophyll b and MDA contents in roots of tolerant variety Guangtian 3.[Conclusion]The study provided basis for the management measures of maize during its seedling stage.

Effects of Waterlogging Stress on Growth and Physiological Index in Cucumber Seedlings

The effects of waterlogging stress on the growth, chlorophyll and MDA content of cucumber seedlings were studied by using cucumber varieties （Cucumis sativus L. cv. Jinyan No.7） as materials. The results show that plant height, leaf number, shoot fresh weight, total root length, total projected area and total surface area of cucumber seedlings showed insignificant differences with those of the control; root fresh weight, root average diameter, total root volume were significantly higher, but the number of root tips and furcation number increased first and then reduced; the chlorophyll content of cucumber seedlings was significantly lower than that of control; MDA content was significantly higher than that of control under waterlogging stress. It was showed that the cucumber was tolerant to waterlogging stress, but the ability of waterlogging stress was limited, and the physiological was significantly hurt and photosynthesis of cucumber seedlings was significantly affected by waterlogging stress.

Effects of Hypergravity on Salt Tolerance of Wheat Seedlings

[ Objective] The study aimed to reveal the effects of hypergravity on salt tolerance of wheat seedlings. [ Method ] The seed germination rate （Gr） and germination index （Gi） of wheat seedlings were measured under hypergravity of 600 × g or 1 000 × g for 4 h and under the stress of 0.4% or 0.9% salt solution. The catalase （CAT） activity and malondialdehyde （MDA） content of wheat seedlings were also measured under 0.4% salt stress. [Result] Compared with seedlings in CK group （no hypergravity or salt stress）, the Gr and Gi of the seedlings in salt stress treatment decreased to different extents; while the Gr and Gi of the seedlings in treatment group （hypergravity and salt stress） increased compared with that in salt stress group. CAT in seedlings of hypergravity treatment was higher than that of CK group and 0.4% salt treatment group, meanwhile the MDA showed an opposite result. [ Conclusion] Hypergravity could enhance the salt resistance of wheat in specific range, and hypergravity of 600 × g for 4 h performed better than that of 1 000 ×g for 4 h.

Changes in Physiological Indexes of SPDS Transgenic Potato Plants under Low Temperature Stress

Using potato plants overexpressing spermidine synthase（SPDS） gene as experimental materials, changes in chlorophyll content, malondialdehyde（MDA） content and superoxide dismutase（SOD） activity of potato leaves under low temperature stress were determined. According to the results, chlorophyll content of experimental plants showed a decreasing trend; MDA content of 01-47 was significantly higher than that of Atlantic; MDA content of 01-6 and 01-49 was significantly lower than that of Atlantic; SOD activity of 01-6 and 01-47 was higher than that of Atlantic. Potato lines 01-6 and 01-47 can be further cultivated to breed new cold-resistant potato varieties.

Study on Effect of Drought Stress with PEG-6000 on Physiological and Biochemical Indicators in Kadsura coccinea

[Objective] The aim was to research drought resistance and adaptation mechanisms of Kaclsura coccinea under different drought stresses. [Method] The seedlings of Kadsura coccinea growing one year were taken as materials in order to investigate and analyze leaf SPAD value, relative water content （RWC）, malonaldehyde （MAD）, cell membrane permeability （RP）, proline （PRO） and superoxide dismutase activity （SOD）. [Result] As drought stress improved, leaf SPAD value and RWC were both diminishing and RWC fell remarkably; MAD, Pro, RP and SOD activity were increasing; MAD and RP grew significantly. [Conclusion] Kadsura coccinea is much sensitive to drought stress and will be affected if water loss is too much high.

Effects of Drought Stress on Morphological and Physiological Indices of New Coix Varieties in Yunnan

In order to study the effects of drought stress on the morphological and physiological indexes of Yunnan Coix at different growth stages, two new varieties of Yunnan Coix Wenyi 4 and Wenyi 5 were used as experimental materials, potted and compared with CK by normal irrigation. Morphological indices such as plant height, stem diameter and physiological indices such as protein, soluble sugar, chlorophyll content and relative conductivity (REC) of the two varieties under drought stress at seedling stage, tillering stage and jointing stage were determined, and data statistics and variance analysis were performed for each index. The results showed that the morphological indices, plant height of Wenyi 4 and Wenyi 5 were significantly affected by drought stress at seedling stage, while the stem diameter was significantly affected by drought stress at seedling and jointing stage. In terms of physiological indices, the relative conductivity, protein and soluble sugar contents of Wenyi 5 increased at a higher degree, whereas chlorophyll content decreased at a higher degree, indicating that Wenyi 5 was greatly affected by drought stress. Through the analysis of drought resistance of the tested materials at different stages by polar ordination method, the results were as follows: jointing stage of Wenyi 5>jointing stage of Wenyi 4>seedling stage of Wenyi 4>seedling stage of Wenyi 5>tillering Stage of Wenyi 4>Tillering Stage of Wenyi 5. For the growth period, the drought resistance was as follows: jointing stage>seedling stage>tillering stage. In conclusion, Wenyi 4 has strong drought resistance and is suitable for droughtresistant cultivation.

Research on Physiological Characteristics of Tall Fescue under Nitrogen Stress

[Objective] This study aimed to investigate the physiological characteristics of tall fescue under nitrogen stress. [Method] A series of physiological changes in protein content, chlorophyll content, enzyme activities and amino acids contents in tall fescue under nitrogen stress were analyzed. [Result] Under nitrogen stress, the leaf chlorophyll content in tall fescue was reduced, and superoxide dismutase（SOD）,peroxidase（POD）, glutamine synthetase（GS） activities were increased. Among the 18 kinds of amino acids analyzed, the contents of asparagine, serine, glycine, glutamine, glutamic acid, aspartic acid, threonine, alanine, arginine, methionine, valine,isoleucine and leucine were significantly reduced in tall fescue under nitrogen stress.[Conclusion] This study will provide certain reference for rational application of nitrogen and exploration of plant ecological potential in the future.