化感物质己二酸二异丁酯对茄子黄萎病及幼苗生长的化感效应

 采用模拟的方法,研究了己二酸二异丁酯对茄子黄萎菌及茄子种子萌发、幼苗生长的化感效应。结果表明,己二酸二异丁酯在黄萎菌培养的前阶段极显著地抑制了菌丝的生长,培养7 d时,1.0 mmol·L^-1的抑制作用最大;11 d时,则促进了菌丝的生长,但未达到显著水平。田间抗病试验结果表明,各浓度己二酸二异丁酯均提高了茄子幼苗对黄萎病的抗性,其中以0.5 mmol·L^-1处理最好。己二酸二异丁酯低浓度时促进了茄子种子的萌发,增加了幼苗的株高、茎粗、地上和地下部干鲜质量、叶绿素含量和根系活力,而随着浓度增大,促进作用减弱或者表现出抑制作用。低浓度的己二酸二异丁酯对叶片丙二醛（MDA）含量和细胞膜相对透性起化感抑制作用,并随浓度增加作用强度增大;但浓度增至1.0 mmol·L^-1时,表现化感促进作用。     

施氮量对间作小麦蚕豆根系分泌大豆异黄酮的影响

通过盆栽和水培试验,采用小麦蚕豆间作、蚕豆单作、小麦单作3种种植方式,研究了不同生育期不同氮水平(低氮、常规氮和高氮)处理下,单、间作小麦和蚕豆根系大豆异黄酮分泌量的变化,为进一步探明间作增产和控病机制提供依据。结果表明,随作物生育期推移,小麦根系分泌大豆异黄酮数量明显减少,蚕豆根系大豆异黄酮的分泌量先增加后减少。随施氮量增加,小麦蚕豆根系大豆异黄酮分泌量均减少,且多达显著水平。与低氮处理相比,常规氮和高氮处理下,单、间作小麦大豆异黄酮分泌量分别显著减少,且多达显著水平。间作可以显著提高作物大豆异黄酮的分泌量,但间作优势仅在低氮和常规氮处理下明显,高氮处理下,单、间作小麦和蚕豆根系分泌大豆异黄酮数量差异不显著,并且这种间作效应会随生育期的推移逐渐消失。总之,间作种植和施氮量均影响作物根系大豆异黄酮分泌量,且低施氮量的影响更明显。     

油松播种苗与豆科植物间的根系磷素营养关系

本文用~(22)P示踪法测定了油松和豆科植物的含磷根系分泌物的组分和数据,并研究了两者的相互关系。据测定,油松的含磷根系分泌物的排出率为15～23％,豆科植物为5～14％。含磷根系分泌物中。水溶性组分约占66～76％,脂溶性组分15～19％,其余为含磷蛋白质。试验证明,在油松与豆科植物之问,存在着明显的含硫化合物交流现象。根据上述材料,作者认为油松与沙打旺、草木间作,在磷素营养方面可能比与小冠花间作更有利。     

Potential of seed and root exudates of the common bean Phaseolus vulgaris L. for immediate induction of rhizobial chemotaxis and nod genes

Abstract

Immediate induction of rhizobial chemotaxis and nod genes by seed and root exudates of the common bean Phaseolus vulgaris L. was investigated. One hour after the onset of Rhizobium incubation in a culture medium composed of common bean exudates and soil extract, a large number of Rhizobium cells were attracted by the seed exudates of all the cultivars (cvs Hokkaikintoki, Himetebou and Kurodanekinugasa), while the media containing root exudates was not statistically different from the control. After 1 h of incubation, the nod genes were induced significantly by the seed exudates of Himetebou and Kurodanekinugasa. In contrast, the seed exudate of Hokkaikintoki and the root exudates of all the cultivars failed to exert a beneficial effect on the immediate induction of the nod genes. These results suggested that the seed exudates displayed a higher potential for immediate induction of rhizobial chemotaxis and nod genes than the root exudates, except for nod gene induction by the seed exudate of Hokkaikintoki.     

植烟土壤根系分泌物障碍的化学原位修复研究

采用小区试验,研究了根系分泌物对烟草的连作障碍效应和3种修复剂的缓解效应.结果表明,根系分泌物对烟草的连作障碍效应非常明显,表现在抑制烟草的生长发育,增加烟草黑胫病发病率.加入3种修复剂均能大大降低根系分泌物对烟株的自然发病率,提高烟株各项经济性状指标,其中以修复剂101效果最好.     

Effects of root exudates of Rj2Rj3- and Rj4-genotype soybeans on growth and chemotaxis of Bradyrhizobium japonicum

Almost all of the soybean cultivars (Glycine max L. Merr.) form nodules on their roots by infection with Bradyrhizobium japonicum. However, it has been observed that the soybean cultivars harboring nodulation conditioning genes, for instance Rj ₂, Rj ₃, and Rj ₄, do not form effective nodules with some strains of B. japonicum. Ishizuka et al. (1991b) classified the rhizobia isolated from field-grown soybeans into nodulation-types A, B, and C based on the compatibility with these Rj-soybean cultivars. Nodulation-type B is incompatible with Rj ₂ Rj ₃-cultivars and type C is incompatible with Rj ₄-cultivars. Nodulation-type A rhizobia are compatible with both Rj ₂ Rj ₃ - and Rj ₄-cultivars. Furthermore, the Rj-cultivars were found to prefer appropriate nodulation-type rhizobia for nodulation, that is, non-Rj-, Rj ₂ Rj ₃ -, and Rj ₄-cultivars prefer nodulation-types A, C, and B rhizobia, respectively (Ishizuka et al. 1991a). In the present study, in order to examine the mechanisms of preference of Rj-cultivars for rhizobial strains for nodulation, root exudates from Rj-cultivars were examined for their effects on the growth rate and chemotaxis of various types of B. japonicum strains.     

辣椒根系分泌物对辣椒种子萌发和幼苗生长的影响

张掖市辣椒连作障碍逐年加重,根系分泌物自毒作用是引起辣椒连作障碍的一个重要因素。为克服辣椒连作障碍,以陇椒2号为试材,研究了辣椒根系分泌物对其种子萌发和幼苗生长的影响。结果表明,不同浓度的辣椒根系分泌物浸提液对辣椒种子萌发和幼苗生长均有一定的抑制作用,根系分泌物浸提液浓度为100 g/kg时对辣椒的生长抑制作用较弱,使辣椒种子的发芽率降低25.66个百分点,使辣椒幼苗的光合速率、蒸腾速率分别下降了0.97、0.25 μmol/(m·s);根系分泌物浸提液浓度为300 g/kg时对辣椒生长的抑制作用最强,使辣椒种子发芽率降低53.33个百分点,使辣椒幼苗的光合速率、蒸腾速率分别降低了3.19、1.35 μmol/(m·s)。可见,根系分泌物对辣椒的抑制作用与其浓度成正比关系。     

c-Fos expression in spinal trigeminal tract neurons of rats induced by intrapericardiac injection of algogenic chemicals

AIM: To identify the correlation between intrapericardial injection of allogeneic chemicals and activation of the rat spinal trigeminal tract (STT) neurons.METHODS: Adult male Wistar rats were anesthetized with urethane and divided into 3 groups: inflammatory exudate solution (IES) group, receiving intrapericardial infusion of IES; negative control (saline) group, receiving intrapericardial infusion of saline; and sham group, undergoing the same surgical procedure without intrapericardial infusion. The expression of c-Fos in the neurons of the cervical spinal cord and brain stem, particularly in the region of the trigeminal sensory nuclear complex, including the principal sensory trigeminal nucleus (Pr5VL), subnucleus oralis (Sp5O), subnucleus interpolaris (Sp5I) and subnucleus caudalis (Sp5C), was analyzed by immunohistochemistry as an index of neuronal activation. RESULTS: Compared with saline group and sham group, the number of c-Fos-positive neurons in IES group increased significantly (P＜0.05). c-Fos-positive neurons were mainly found in the dorsal horns of laminae I-V at C2, as well as at the rostral edge of the Pr5VL, Sp5O, Sp5I, and Sp5C. The number of c-Fos-positive neurons gradually increased from bregma to interaural line at the pyramidal decussation. Interestingly, fewer c-Fos-positive neurons were observed on the right side than that on the left (P＜0.05).CONCLUSION: Intrapericardial injection of algogenic chemicals activates STT neurons, possibly underlying the phenomenon whereby cardiac ischemia causes craniofacial pain.     

土壤改良对越橘根域细胞分裂素含量及年变化规律的影响

【目的】研究不同土壤改良物质对越橘Vaccinium vitis-idaea根际土和非根际土中细胞分裂素[玉米素(Z)、玉米素核苷(ZR)和异戊烯基腺苷(iPA)]含量及年变化规律的影响.【方法】以2年生盆栽越橘为试材,应用"根际微区土壤剥落分离法"收集与根系黏着程度不同的非根际土和根际土样品,用高效液相色谱法测定土壤样品细胞分裂素含量.【结果和结论】不同根域处理的根系分泌物中,玉米秸秆配施氮肥处理(k4)的细胞分裂素含量最高,其他依次为添加玉米秸秆处理(k3)、添加草炭处理(k2)、无添加(k1,对照);不同时期越橘根际土和非根际土中细胞分裂素含量总趋势为ZZRiPA,如k4处理的Z、ZR和iPA平均质量比分别为9.89、9.76和3.57 ng/g,分别比k1(对照)高出67.9%、84.2%和105.6%.越橘根系细胞分裂素含量年变化规律表现为早春时期呈上升趋势,秋末季节含量呈下降趋势,而在早春至秋末之间,根系分泌物含量较高.