干旱胁迫下BR与N、P、K配合对羊草生长及抗旱性的影响

受气候变化如干旱胁迫作为危害羊草主要的环境因子之一,对其生产力的提高产生了严重的影响。通过盆栽人工控水法,研究在正常(土壤相对含水量为80%)和干旱(土壤相对含水量为50%)条件下油菜素内酯(BR)与氮、磷、钾(N、P、K)配合处理对羊草幼苗生长及其抗旱性的影响。结果表明:适当浓度的BR可以减轻干旱胁迫对植株的伤害,而BR与N、P、K配合(1%尿素+1%磷酸二氢钾+0.10 mg·L^-1 BR)则可进一步促进植株生长和营养物质的积累,提高羊草的抗旱性,效果更好。这种效应与其调控植株生长,提升渗透调节能力,降低膜脂的过氧化作用,增强抗氧化酶活性等生理特性密切相关。配合处理下羊草的株高、鲜重、干重和根系活力比干旱对照(CK₂)分别增加28.96%、62.46%、45.21%和19.08%,N、P、K含量分别增加20.74%、236.84%和42.31%,营养代谢相关酶硝酸还原酶(NR)、酸性磷酸酶(ACP)和苹果酸脱氢酶(MD)活性发生改变,脯氨酸、可溶性蛋白和可溶性糖分别增加57.20%、22.82%和5.94%,而丙二醛和叶片电导率分别降低37.42%和55.79%,超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)、谷胱甘肽还原酶(GR)和抗坏血酸过氧化物酶(APX)分别增加158.40%、38.15%、32.97%、30.00%和28.74%。     

油菜素内酯在不同生育期对两品系甘蓝型油菜的生长调控

为了解油菜素内酯对甘蓝型油菜品质及弱光反应的影响，以湘油15号的2个辐照突变品系（含油量和产油量明显不同的XY881和XY883）为材料，研究表油菜素内酯（epibrassinolide, 2,4-BL）在不同生育阶段对甘蓝型油菜生长发育的影响。通过盆栽试验和2014-2016年两年度田间试验，分析2,4-BL对种子萌发、营养生长、产油量及相关构成因子的影响。结果表明，2,4-BL对2品系的影响具有相似规律，包括：对种子萌发具有剂量效应，低浓度下促进种子萌发，高浓度下抑制种子萌发；在全生育期低剂量的2,4-BL促进主茎伸长、提高光合效率、促进结实，但不影响成熟种子大小和含油量；在盛花后使用，延缓种子成熟而造成授粉后40 d种子含油量下降；长期短间隔使用2, 4-BL降低调控作用。在分子水平上，2,4-BL诱导油菜素类固醇信号通路和光信号通路关键转录因子BnaPIF4、 BnaBZR1 和BnaBES 的基因表达。推测2,4-BL通过诱导甘蓝型油菜中油菜素内酯和光信号途径相关转录因子基因表达，激活下游调控的基因网络，通过促进光合作用延长营养生长时间、促进主茎生长和结实，进而影响产油量。因此认为表油菜素内酯可以作为生长调节剂在油菜生产中使用，建议低浓度或长间隔施用，且尽量在油菜盛花期之前使用。     

Brassinolide Application Improves the Drought Tolerance in Maize Through Modulation of Enzymatic Antioxidants and Leaf Gas Exchange

Brassinolides (BRs) are naturally occurring substances, which modulate plant growth and development events and have been known to improve the crop tolerance to abiotic stresses. In this study, possible role of exogenously applied brassinolide (BR) in alleviating the detrimental effects of drought in maize was evaluated in a rain‐protected wire‐house. Maize was subjected to drought at the start of tasseling for 6 days by withholding water application followed by foliar spray of BR (0.1 mg l^?1) to assess the changes in growth, gas exchange, chlorophyll contents, protein, relative leaf water contents (RLWC), proline, malonialdehyde (MDA) and enzymatic antioxidants. Drought substantially reduced the maize growth in terms of plant height, leaf area and plant biomass. Moreover, substantial decrease in gas exchange attributes (net photosynthetic rate (A), transpiration rate (E), stomatal conductance (g_s), water use efficiency (WUE), instantaneous water use efficiency (WUEi) and intercellular CO₂ (C_i) was also recorded. However, exogenous application of BR remarkably improved the gas exchange attributes, plant height, leaf area, cobs per plant, seedling dry weight both under drought and well‐watered conditions. BR‐induced promotion in growth and physiological and metabolic activities were mediated through increased protein synthesis enabling maintenance of tissue water potential and activities of antioxidant enzymes lowering the lipid peroxidation under drought.     

油菜素内酯在棉花组织培养中的应用研究Ⅰ．油菜素内酯对陆地棉体细胞胚胎发生和根器官发生的影响

本文研究了ＢＲ及其与ＩＡＡ、２，４－Ｄ、ＫＴ和６－ＢＡ等配合使用对陆地棉愈伤组织诱导、继代、分化、体细胞胚胎和根器官发生的影响。ＢＲ０．０１ｍｇ／Ｌ能使陆地棉Ｃｏｋｅｒ２０１、３１２两品种分化产生胚性愈伤组织，并有效地保持该种愈伤组织的生活力和胚胎发生能力。ＢＲ０．０１ｍｇ／Ｌ＋ＩＡＡ０．５ｍｇ／Ｌ促进Ｃｏｋｅｒ２０１、３１２两品种体细胞胚胎发生，ＢＲ０．０１ｍｇ／Ｌ＋２，４－Ｄ０．０５ｍｇ／Ｌ能诱导所有供试品种产生疏松黄绿色愈伤组织，２，４－Ｄ用量逐步降低或除去后，一些品种便分化产生胚性愈伤组织或体细胞胚状体。另在ＢＲ与ＩＡＡ的某些组合中还观察到根器官的发生。     

BR与 S3307复合剂对黄瓜生理指标和产量的影响

油菜素内脂（BR）与烯效唑（S3307）复合剂处理黄瓜幼苗提高了叶片的叶绿素含量。光合速率，SOD酶活性和MDA含量降低，相对电解质渗透显降低，幼苗的根系活力显提高。田间试验结果表明，BS处理比对照增产11.62%，瓜数增加17.72%，因此，BR和SS3307复合剂在生产上有一定的应用推广价值。     

油菜素内酯对辣椒果实贮藏及抗氧化能力的影响

为探究油菜素内酯(BR)对辣椒果实贮藏效果及抗氧化能力的影响,采用浓度为1、10、20和30 μmol·L-1的24-表油菜素内酯(24-epibrassinolide,EBR)处理辣椒果实,然后分别在温度4℃和25℃,湿度70％～80％下贮藏,检测果实失重率、腐烂率和冷害指数以及最适EBR浓度处理下辣椒果实丙二醛(MDA)和总抗氧化能力的变化.研究结果表明,EBR处理浓度20 μmol.L-1,温度4℃较适宜辣椒贮藏,能有效降低辣椒的失重率和腐烂率,且出现腐烂的时间延迟.在4℃低温下,较其他3种浓度的EBR处理,20.tmol.L-1处理的辣椒冷害指数降低,出现冷害现象的时间延迟.与对照相比,外源最适EBR处理,有效抑制了辣椒果实MDA含量的积累,减缓了总抗氧化能力的下降,其中4℃+ 20μmol.L-1 EBR处理,显著抑制了辣椒果实MDA含量的积累和总抗氧化能力的降低,较好地保持了辣椒果实中抗氧化酶的活性,保护细胞膜的完整性和功能性,减少营养的流失,维持辣椒的感官品质和营养品质,延长辣椒的贮藏时间.该研究为辣椒果实的贮藏保鲜提供新的参考与路径.     

Recovery Effect of Root Soaking in Brassinosteroid (BR) on Transplanting Shock of Hydroponically Grown Long-Mat Rice Seedlings Under Mechanical Transplanting

【Objective】Mechanical transplanting results in serious transplanting shock of rice seedlings and a longer recovery stage, which negatively impacts the growth of rice seedlings in the paddy field and the yield formation of machine-transplanted rice. The objective of the research is to investigate the effects of brassinosteroid (BR) soaking on transplanting shock and grain yield of hydroponically grown long-mat seedlings (HLMS) under mechanical transplanting. 【Method】We analyzed the effects of different concentrations of BR (CK, T1, T10, T20, BR concentrations of 0 mg/L, 1 mg/L, 10 mg/L, 20 mg/L in the nutrient solutions, respectively) soaking on morphological traits, dry matter accumulation, antioxidant system, endogenous hormone concentrations and grain yield of HLMS under mechanical transplanting. 【Result】Root soaking in BR could promote above-ground part growth of rice, the plant height under T1, T10, T20 was 11.68%, 8.12% and 7.61% higher than CK, respectively; and the effect on the root was more obvious, BR soaking significantly increased the root length, root surface area, root tip number, root volume, root diameter, root weight and root/shoot ratio. At low BR concentration, root tip overnumbered that at high BR concentration while other root system indicators were better under high concentration BR treatment. Compared with CK, BR (T1, T10, T20) soaking decreased the H2O2 content in leaves by 12.50%, 23.25% and 22.25% 12 days after transplanting, respectively, and increased the activities of antioxidant enzymes. Compared with the day of transplanting, the zeatin (ZT) concentration in the leaves under BR soaking treatments increased rapidly (197.27%, 153.11% and 243.78%, respectively), while under CK treatment it increased slowly (2.94%), the root performance was consistent with leaves, and the auxin (IAA) concentration in the roots was significantly higher than that of CK on the second day after transplanting. The gibberellin (GA3) content of roots in BR soaking treatments was significantly higher than that of CK within one week after transplanting. Compared with CK, T10 significantly increased the number of spikelet per panicle by 15.04%, and the seed-setting rate by 6.62%. T20 obviously increased the seed-setting rate by 6.17%. However, T1, T10, and T20 notably decreased 1000-grain weight. The grain yield under T10 and T20 treatments (the corresponding values were 10.58 t/hm2 and 10.84 t/hm2) were 5.11% and 7.99% higher than CK (10.04 t/hm2), while grain yield under T1 (9.68 t/hm2) was 3.58% lower than that of CK, and there was no significant difference among these treatments. 【Conclusion】Briefly, BR （T10, T20）soaking at proper concentrations could mitigate the transplanting shock, increase antioxidant enzymes activities, decrease H2O2 content of leaves, improve the contents of ZT, GA3, and IAA to different extent, efficiently promote roots growth, increase the number of spikelet number per panicle and seed-setting rate of HLMS under mechanical transplanting. This study will lay a theoretical basis and provide technical reference for reducing machine-transplanting shock and promoting high and stable yield of mechanical transplanted rice.     

天然油菜素内酯对油松和刺槐种子发芽的影响

油菜素内酯是一种新型植物甾体激素 ,近年来 ,在农业上得到了广泛的应用 (郭奇珍 ,1 983;李凯荣等 ,1 998;骆炳山 ,1 986;赵毓橘等 ,1 986;朱广镰 ,1 992 ;Ｉｋｅｋａｗａｅｔａｌ.,1 991 ;Ｍａｎｄａｖａ ,1 988;Ｙａｍａｇｕｃｈｉｅｔａｌ.,1 987)。但在林业上的研究报道甚少 ,特别是油菜素内酯对林木种子萌发及下胚轴伸长的影响未见报道。本文以水土保持林主要树种———油松 (Ｐｉｎｕｓｔａｂｕｌａｅｆｏｒｍｉｓ)、刺槐 (Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ)种子为材料 ,研究了天然油菜素内酯对其萌发及下胚轴伸长的影响 ,以便…