光质对火焰无核葡萄胚挽救及试管苗生长发育的影响

以火焰无核自交胚珠为试材,研究了红光、蓝光、白光及暗处理对胚发育、胚萌发及试管苗生长发育的影响。结果表明:3种光质处理对胚发育均有一定促进作用,但与对照未达到显著性水平。在胚萌发阶段,红光对胚萌发有明显的促进作用。在试管苗发育成苗阶段,以蓝光处理的试管苗最为矮壮,红光下葡萄胚挽救苗试管苗节间最长,发育最高,叶绿素含量最低;各处理试管苗继代后移栽成活率均可达到90%以上。     

基质对葡萄胚培苗移栽成活率的影响

研究了不同杂交组合在不同基质条件下的胚培苗移栽成活率。结果表明:在草炭:蛭石:园土:马粪(5:1:1:1),附加200g蔬菜壮苗母剂的母质中成活率达到了84%以上。并分析了影响成活率的原因。     

棉花小知识:有机棉花无土育苗及无钵移栽法

正它主要是根据有机棉花苗期各生长阶段的营养特点,科学配制工业化营养液来满足棉苗生长需要,使棉苗壮苗早发,二叶一心期适于移栽时配以专利技术生根剂处理,使有机棉花移栽后迅速生根,快速成活,成活率高,缓苗期短,根系发达,达到壮苗早发的目的。下面为大家介绍有机棉花无土育苗及无钵移栽法:壮苗、早发用该技术培育的棉苗,营养全、苗子壮,经过特殊炼苗技术处理,棉苗抗逆性强,早发。成活率高。成活率达95%以上,正常操作可达     

过氧化钙增氧对漂浮育苗烤烟生长的影响

为解决漂浮育苗过程中烟苗遭受低氧胁迫,研究了过氧化钙增氧的效果以及对烟苗的根系活力、生物量、植物学性状和烟株大田生长的影响。结果表明:营养液中添加过氧化钙可提高溶解氧含量,提高根系活力、生物量和根冠比,缩短移栽后还苗时间,促进大田烟株生长。其中,过氧化钙浓度为450 g/m3的处理效果最好,与对照比,根系活力、总生物量干重、根冠比显著提高了87.5%、18.8%、14.15%,烟苗移栽后,还苗时间缩短3.4 d,自然株高提高12.1 cm。      

葡萄幼胚试管苗移栽技术

葡萄幼胚试管苗移栽技术本文于１９９８－０１－２０收到。汤小宁潘春云亓桂梅杨立英（山东省酿酒葡萄科研所，２５０１００）在利用胚挽救技术培育无核葡萄新品种的研究中，葡萄幼胚试管苗移栽是非常重要的环节。因此，我们从１９９４年起，对该技术进行了专项研究，在借...     

栽植苗叶面施肥安全浓度试验简报

烤烟在移栽前1～2天采用叶面喷施营养液的方法,既能增加烟苗体内无机养分,又可解决土施“送嫁肥”必须浇水而影响锻苗的难点,是一项简便易行的经济有效的促进栽后烟苗早长快长的措施。叶面营养液的喷洒浓度低时,虽然安全,但对烟苗补充无机养分少,作用不大;提高喷洒浓度,补充养分效果好,但过浓时易发生烧苗。因而研究移栽苗叶面施肥的安全浓度,具有较大的实用价值。一、供试烟苗经过锻苗处理的10片叶龄、不同品种(NC82、NC89、G-140、G-28、K394、K326、小黄金     

三倍体葡萄胚挽救育种研究现状与展望

综合分析国内外相关文献,阐述了三倍体葡萄胚挽救技术的研究进展,探讨了影响三倍体葡萄胚挽救育种成功的主要因素:亲本选择、接种时期、培养基种类等,概述了三倍体葡萄鉴定方法,驯化移栽过程中的影响因素,包括基质类型、生根粉浓度等,并对胚挽救技术在三倍体葡萄育种上的发展进行展望。     

烤烟漂浮育苗营养液增温配套措施研究

为了抵御倒春寒对烟苗生长造成的不利影响,研究了漂浮育苗营养液增温的7种不同方式及其对烟苗生长的影响。结果表明,7种不同增温措施均可在温度较低的夜间将营养液温度控制在25~28 ℃,提高室内温度及基质温度3~4℃;烟苗出苗及漂浮育苗期分别缩短7、20 d以上;出苗率和烟苗素质明显提高。     

基于营养液自动循环系统的烟草育苗方式

为解决烟草漂浮育苗中由于营养液静止不动而导致的根系生长受阻及烟苗生长不均匀的问题,对现有育苗设施进行了改造,研发了营养液循环系统,增加自动循环装置,并研究了基于营养液循环系统的烟草育苗方式.结果表明:与常规育苗方式对比,循环系统育苗营养液中的溶解氧浓度增加至2.24mg/L,烟苗根长、根系生物量显著提高,且生长速度加快,成苗期比对照(CK)提早9d,烟苗叶绿素、可溶性蛋白、游离氨基酸含量升高,生理素质提高.因此,营养液循环系统育苗方式有利于烟草壮苗的培育.     

干旱胁迫对不同育苗方式烤烟生长和生理生化特性的影响

为明确干旱胁迫对不同育苗方式下烟苗移栽后的生长状况及生理生化特性的影响,通过盆栽控制土壤含水率试验,研究了干旱缺水环境下烤烟的适宜育苗方式.结果表明:干旱胁迫下,烟株脯氨酸含量和过氧化物酶活性两项指标均呈现出上升趋势.随着干旱时间的持续以及干旱程度的加深,烟株的硝酸还原酶活性则呈下降趋势.在轻度干旱条件下,漂湿育苗方式培育的烟苗移栽后生长状况好于漂浮育苗方式培育的烟苗.在极端干旱条件下,烟苗移栽14d后,两种育苗方式的烟株生长均停滞并出现叶片变黄枯萎等现象.     

沼液对烟苗生长及生理特征的影响

在有机烟叶生产中,为替代化学肥料,提高有机肥源在烤烟育苗中的利用效率,以烤烟育苗专用肥为对照(CK), 研究沼液营养液氮浓度分别为50、150、250 mg/L 对烟苗生长及生理特性的影响。结果表明,与CK 相比,氮浓度为50 mg/L 的处理烟苗矮小,营养液中的养分难于满足烟苗生长的需要;氮浓度为150 mg/L 的处理烟苗长势较好,能显著增加烟苗根系的干、鲜质量,同时,总根长、根表面积、体积、根系活力均有不同的程度的增加。而叶片中光合色素含量、光合特性、 生理特性各指标与CK 相比差异不大。综合来看,氮浓度为150 mg/L 的处理能够达到使用漂浮育苗专用营养液的效果,可用于有机烟草育苗生产。     

烤烟湿润育苗技术研究

对以育苗基质和营养液配方的筛选、肥水管理方式的改进和不同育苗方式比较为主要内容的烤烟湿润育苗技术进行了探讨。结果表明,10号育苗基质配方和2号营养液配方所育烟苗综合素质最高,茎高、茎围适中,根系发达,根系活力强,根茎叶干鲜重最重;育苗肥水管理方式由传统的"一段式"改为"前期浅灌、后期浇施"的"二段式",不仅大大降低了烟农的育苗用工,而且解决了肥水单纯采用浇施,导致基质易板结、出苗率较低、生长不整齐等问题;与漂浮育苗相比,该技术不仅保持了漂浮育苗的优势,同时提高了成苗期烟苗的素质,有效地解决了返苗期偏长的问题。     

PRODUCTION OF NICOTINIC ACID BY BAKER'S YEAST GROWING IN NITROGEN-RICH AND NITROGEN-POOR MEDIA

The biosynthesis of nicotinic acid by baker's yeast was investigated in laboratory-scale aerobic batch cultivation in nitrogen-rich and nitrogen-poor nutrient solutions. Biosynthesis, which occurred parallel with yeast growth, was vigorous during the exponential growth phase and almost ceased during the retardation phase. The amount of nicotinic acid synthesized per batch was dependent on the nitrogen content of the solution. When a small inoculation of seed yeast was used, the amount of nicotinic acid synthesized per unit weight of yeast formed and the nicotinic acid content of the yeast did not depend on the nitrogen concentration of the nutrient solution. With a large inoculum, both the amount of nicotinic acid synthesized per unit weight of yeast produced and the nicotinic acid concentration of the yeast decreased with the nitrogen concentration of the nutrient solution. Calculated as μg. per g. of protein formed, the amount of nicotinic acid synthesized and the nicotinic acid concentration in the yeast were higher in the nitrogen-poor medium than in the nitrogen-rich medium when a small inoculum was used, but lower when large amounts of seed yeast were used.     

Studies on potassium nutrition of plants III.—Effects of potassium concentration on growth and mineral composition of vegetable seedlings in solution culture

Because of diffusion, the effective concentration of nutrients in contact with plant roots in sand culture is much less than the concentration of the nutrient solution supplied. For comparison with earlier observations in sand culture, solution culture experiments have been made with cabbage and red beet seedlings using readily available equipment for the control, within reasonable limits, of the potassium concentration of the root environment. Weight responses and K content of tops and roots, Na content of tops, top: root weight ratios, percentage dry residue of top and root and potassium flux through the roots were influenced in similar ways by increase of K⁺ concentration in the medium. There were steep slopes to about K_0·1 followed by an abrupt change of slope and levelling off or a slight fall at the highest potassium concentrations. The weight responses, K content of top and root and potassium flux increased with increasing nutrient medium K⁺ concentration whereas the other relationships were in the reverse direction. Root potassium contents increased in a similar manner to those of the tops but were lower than the latter at corresponding medium K⁺ concentrations. Root sodium contents rose to a maximum at a medium concentration of 0·1 mequiv./1 of K⁺ and thereafter fell with increasing potassium in the medium. The sums of the cation equivalents (K, Na, Mg, Ca) in the tops and roots were approximately constant. The limiting potassium concentration was determined from the response curves as the lowest concentration at which maximum yield was obtained. For beet in solution culture, the value was 0·15 and the corresponding concentration in sand culture was 0·7 mequiv./1 (ratio, sand/solution = 4·7); the values for cabbage were, respectively, 0·13 and 0·5 mequiv./1 (ratio, 3·8). The rate of removal of potassium by beet seedlings from solutions containing initial concentrations in the range 0·01-5 mequiv./1 was determined. The flux of potassium through the root surfaces varied from 0·35–1·89 μg K/g root/sec with increasing initial concentration in the medium.     

恩施烟区培育壮苗的加热技术研究初报

通过对育苗池底施加不同功率的地热线,拟探索通过苗床加热提高漂湿育苗营养液和盘面温度满足烟苗生长发育,为恩施烟区培育适时烟草壮苗提供科学的育苗方法。研究结果表明,育苗池底铺加地热线均能提高育苗温度和烟苗的生长速度,有效缩短烟苗育苗时间,促进了烟苗生物量的积累,烟苗的整体素质有一定提高。因此,结合恩施烟区地理特征,低山、二高山和高山烟区可分别在育苗池内底部铺加10、20和40 W/M²功率地热线加热,满足烟苗生长所需的温度条件,确保烟苗适时移栽。     

烟草简易型直播漂浮式育苗技术研究

研究了烟草的直播漂浮式育苗,包括基质、育苗盘、施肥、剪叶及炼苗等方面的试验。开发出适合中国实际的简易型配套技术。应用该技术可生产出均匀、健壮的烟苗。与传统的营养土两段育苗相比,成本降低78%,劳力节省91.7%,苗床面积减少91.7%。成功地开发出炭化谷壳和炭化玉米德轴两种新质。试验证明,其育苗效果与蛙石、泥炭、白云母、岩棉等相当,且成本低廉,不滋生藻类。育苗盘以200型成苗质量最佳。起始营养增添微量元素并在出苗后20天添加一次营养液。剪叶频率以4天为宜。成苗后控制水肥炼苗,以4~6天较好。      

高蛋白全营养液工艺配方优化研究

研究了影响高蛋白全营养液稳定性的因素,确定了加工营养液的最佳工艺和配方。得到的高蛋白全营养液呈淡褐色,均匀,无分层现象,静置一段时间后无上浮,口感良好,无豆腥味。高蛋白全营养液所含各种营养成分比例适当,中链脂肪酸和长链脂肪酸比例合理,可口服或管饲,能满足病人各种营养需要。     

Efficacy of gamma radiation and aqueous chlorine on Escherichia coli O157:H7 in hydroponically grown lettuce plants

Interaction of Escherichia coli O157:H7/pGFP with hydroponically grown lettuce plants was evaluated in this study. Lettuce seedlings were planted in contaminated Hoagland's nutrient solution and thereafter subjected to gamma radiation at 0.25, 0.5, and 0.75 kGy, and aqueous chlorine at 200 ppm. There was no trace of E. coli O157:H7/pGFP in lettuce leaves harvested from noncontaminated nutrient solution (control); however, for plants grown in contaminated nutrient solution, the pathogen was recovered from the leaves disinfected with 80% ethanol and 0.1% mercuric chloride. Most of the lettuce seedlings grown in contaminated nutrient solution tested negative for E. coli O157:H7/pGFP under controlled conditions. Gamma radiation at 0.25 and 0.5 kGy, and aqueous chlorine at 200 ppm failed to eliminate E. coli O157:H7/pGFP in lettuce tissue completely; however, the bacteria were not detected in 0.75-kGy treated plants. The presence of E. coli O157:H7/pGFP in lettuce leaves is an indication that the pathogen migrated from the contaminated hydroponic system through the roots to the internal locations of lettuce tissue. Due to inaccessibility and limited penetrating power, aqueous chlorine could not eliminate the bacteria localized in the internal tissue. Findings from this study suggest that gamma irradiation was more efficacious than was aqueous chlorine to control internal contamination in hydroponically grown lettuce. Gamma irradiation is a process that processors can use to inactivate E. coli O157:H7 and therefore, consumers benefit from a safer food product [corrected]     

干旱胁迫下外源ALA对烤烟幼苗光合特性和抗氧化能力的影响

为进一步探究外源5-氨基乙酰丙酸（ALA）对干旱胁迫下烟草幼苗抗旱能力的作用机理,以烤烟品种豫烟10号幼苗为试验材料,采用营养液培养的方法,研究叶面喷施不同浓度的（0~80 mg/L）外源ALA对干旱胁迫下烤烟幼苗烤烟光合特性和抗氧化能力的影响。结果表明干旱胁迫下烤烟叶片细胞活性氧和硫代巴比妥酸（TBARS）含量增加,叶绿体遭到破坏,光合速率降低,植物生长受到抑制。干旱胁迫下外源ALA能够显著降低烤烟叶片活性氧水平,提高抗氧化酶活性,以喷施20 mg/L ALA效果最为显著。其中与PEG处理相比,净光合速率（P_n）、蒸腾速率（T_r）、气孔导度（G_s）分别提高96.19%、96.79%和132.43%,抗氧化物酶（SOD、POD、CAT、APX）活性分别提高49.05%,61.97%,64.17%和70.08%。喷施适宜浓度的外源ALA可有效提高烤烟叶片光合特性和抗氧化能力,缓解活性氧伤害,从而增强烤烟幼苗对干旱胁迫的适应能力。