11个葡萄品种在乐山地区的花芽分化规律     

张顺英  周勇  刘忠  钟倩  周世彬 《落叶果树》2020,52(3):18-21

研究了11个葡萄品种3年生树在四川乐山地区避雨栽培条件下的花芽分化表现。结果表明,结果母枝的花芽分化率,魏可、维多利亚、黑芭拉多、金手指、金优2号和巨玫瑰6个品种的都高于50%,较易形成花芽;户太8号、巨峰、夏黑的在43%~48%;美人指和红指较难形成花芽。结果母枝不同节位的花芽分化率,多数品种在第3节位≥50%;结果枝上花穗着生节位在第3.8~4.9节,其中双花率以巨玫瑰、巨峰和户太8号较高,分别为83.45%、73.61%和73.06%。以结果母枝的花芽分化率≥50%节位作为冬剪的最低节位,则金优2号、户太8号、巨玫瑰、金手指、维多利亚5个品种在第3~4节,黑芭拉多和巨峰2个品种在第2~3节,魏可在1~2节。夏黑表现花芽分化率较低,为43.33%,可能与夏黑不耐弱光有关,设施栽培时应加强透光性。  相似文献   

三角形接法三绕组单相电容电动机瞬态分析     

邓建国  罗隆福彭晓 《湖南农业大学学报(自然科学版)》2004,31(5)

对三角形接法的三绕组单相电容感应电动机的瞬态过程进行仿真分析．为了得到瞬态特性，建立了三角形(△)接法的三绕组单相电容感应电动机在αβ坐标系下的瞬态数学模型，编写计算机仿真程序，通过实例对三角形接法的三绕组单相电容感应电动机的瞬态过程进行仿真计算；用对称分量法分析了三绕组单相电容感应电动机最小不对称运行时需要满足的条件，并由此初步计算电容的数值，然后通过计算机仿真加以确定．对仿真结果进行分析．仿真结果表明：三角形接法三绕组单相电容运转电动机起动转矩较小，适合于对起动要求不高的风机泵类负载；对于起动要求较高或较大的恒转矩负载，可采用双值电容来实现．三角形接法三绕组单相电容电动机带负载的能力约为三相感应电动机在额定电压下对称运行时的0．7倍左右．  相似文献   

苹果梨花芽孕育期生长锥细胞超微结构的观察   总被引：1，自引：0，他引：1  

郭金丽  张玉兰  郝喜龙 《果树学报》2001,18(4):213-216

利用透射电镜对苹果梨花芽孕育期芽内生长锥细胞进行了观察，结果显示，在花芽孕育形成的过程中，生长锥细胞的超微结构发生了一系列变化：蛋白体和脂类小滴逐渐增加；核外膜向外延伸到胞质中与内质网相连，其上分布的核糖体增多；线粒体和内质网数目丰富且分布均匀；核糖体大量游散在胞质中；质体呈浅裂，中央缢缩；微管分布于靠近质膜处等。以上超微结构的变化表现出细胞旺盛分裂和分化的特点，反映了花芽孕育过程中的细胞学特征。  相似文献   

运动磁场具有电场的特性——电磁关系之一(英文)   总被引：1，自引：0，他引：1  

陈有君 《内蒙古农业大学学报(自然科学版)》2001,(4)

综合经典电磁学中关于电与磁联系的基本实验定律及理论 ,经推导和分析得出电场与磁场的联系是 :运动磁场具有或表现出电场的特性 ,当一个具有磁感应强度为 B的场 ,以速度 V运动时 ,这个场的电场强度为 :E=B× VB。磁场的时变必然是由于磁场的运动所至 ,而运动的磁场具有电场的性质 ,因此所谓时变磁场产生电场只不过是运动磁场具有电场特性这一自然规律在特定条件下的一种表现。经典电磁学中把磁场分为静磁场和时变磁场是不合理的。因为与静止相应的是运动而不是时变。磁场的时变和磁场的电特性是伴生关系 ,而非因果关系 ,它们都是磁场运动的结果。所以时变磁场产生电场或者 Faraday- L enz定律不是一个普适的自然规律。但在有些条件下 ,运动磁场和其电场特性之间在数量上确实满足 Faraday- L enz定律 ,因此 ,作为一个从实验中总结出的规律 ,并有一定的理论根据 ,它可以在一些领域中作为数学工具用  相似文献   

水稻中系8541与中系8240光合特性的比较研究     

郭宗华  张其德 《北京农学院学报》1993,(2)

本文通过光合作用参数的测定,详细的研究了中系8541和8240两种不同产量水平的水稻品种的光合特性.论述了在含等量叶绿素的条件下,中系8541和中系8240之间在对光谱的吸收、叶片的光合作用量子转化效率,叶绿体的PSⅡ(光系统Ⅱ)潜在活性(Fv/F_0)和原初光能转化效率(Fv/Fm等的主要区别.实验结果说明,上述各光合作用参数中系8541都优于中系8240.不仅如此.在Mg~(2+)作用下,Fv/Fo和Fv/Fm比值的提高以及Mg~(2+)对两个光系统激发能分配的调节能力中系8541也强于中系8240.  相似文献   

柠檬桉,蚬木硝酸还原酶活力的比较     

吕成群 《热带作物学报》1992,13(2):43-49

柠檬桉9年生单株的材积是蚬木的32.1倍。经不同浓度KNO_3、不同光照强度诱导后,柠檬桉不同叶龄叶的NR(硝酸还原酶)活力均明显高于蚬木。柠檬桉成年树中龄叶片NR活力提高的速度在4h内比蚬木的快2.3倍,而蚬木的NR活力衰减速率在4h内比柠檬桉的快35％。在不同浓度KNO_3溶液中,柠檬桉幼苗吸收NO_3~-量是蚬木的3～10倍,柠檬桉幼苗NO_3~-溢泌量是蚬木的3倍左右。  相似文献   

Acquired resistance triggered by elicitins in tobacco and other plants   总被引：17，自引：0，他引：17  

Philippe Bonnet  Eva Bourdon  Michel Ponchet  Jean -Pierre Blein  Pierre Ricci 《European journal of plant pathology / European Foundation for Plant Pathology》1996,102(2):181-192

Elicitins are a family of proteins excreted byPhytophthora spp. They exhibit high sequence homology but large net charge differences. They induce necrosis in tobacco plants which then become resistant to the tobacco pathogenPhytophthora parasitica var.nicotianae. In stem-treated plants, resistance was not restricted to the site of elicitin application, but could be demonstrated by petiole inoculation at all levels on the stem. Resistance was already maximum after two days and lasted for at least two weeks. It was effective not only towardsP. p. var.nicotianae infection, but also against the unrelated pathogenSclerotinia sclerotiorum. In contrast to dichloroisonicotinic acid, an artificial inducer of systemic acquired resistance, which was increasingly effective with doses ranging from 0.25 to 5mole per plant, the basic elicitin cryptogein exhibited a threshold effect, inducing near total resistance and extensive leaf necrosis above 0.1 nmole per plant. Between 1 and 5 nmole, acidic elicitins (capsicein and parasiticein) protected tobacco plants with hardly any necrotic symptom. Elicitins exhibited similar effects in various tobacco cultivars andNicotiana species, although with quantitative differences, but induced neither necrosis nor protection in other SolanaceÆ (tomato, petunia and pepper). Among 24 additional species tested belonging to 18 botanical families, only some BrassicaceÆ, noticeably rape, exhibited symptoms in response to elicitins, in a cultivar-specific manner. Elicitins appear to be natural specific triggers for systemic acquired resistance and provide a tool for unraveling the mechanisms leading to its establishment.Abbreviations AR acquired resistance - HR hypersensitive response - INA 2,6-dichloroisonicotinic acid - Ppn Phytophthora parasitica var.nicotianae - SAR systemic acquired resistance  相似文献   

Preliminary results of using in vitro axillary and adventitious buds in mutation breeding of Chinese gooseberry     

Xiao-Shan Shen  Jue-Zhen Wan  Wei-Yi Luo  Xiao-Ling Ding 《Euphytica》1990,49(1):77-82

Summary Aseptically cultured shoots of Chinese gooseberry exhibited growth disorder and morphological aberrances, and some died after being exposed to sufficient gamma-ray irradiation. The death rate was dose dependant and the LD₅₀ was 80–90 Gy and 50–60 Gy respectively for cv. Hayward and clone 4. All petiole explants irradiated with gamma-ray could form calli as the control, but the rate of differentiation of adventitious shoots of the petiole explants decreased and was dependant on dose. Sensitivity of the shoot or petiole explants to gamma-ray irradiation varied with species. Gamma-ray irradiation did not deter either the 2-node segments from producing axillary shoots M₁, M₂, and M₃ or the advantitious shoots originating in the petiole explants and the M₃ shoots from forming advantitious roots. Therefore, using aseptically cultured axillary or adventitious buds for mutation breeding of Chinese gooseberry is feasible. A bacterium surviving in the explants lessened the efficiency of these two in vitro techniques in mutation breeding of Chinese gooseberry.Abbreviations IAA 3-indole acetic acid - IBA -indole butyric acid - MS Murashige & Skoog (1962)  相似文献   

Seasonal pattern of shoot emergence and its endogenous control in horsenettle (Solanum carolinense L.)     

KATSURA MIYAZAKI  MISAKO ITO  SHUJI URAKAWA 《Weed Biology and Management》2005,5(1):14-18

Controlling established horsenettle plants is achieved by suppressing shoot emergence from root systems. The seasonal pattern of shoot emergence and its possible endogenous control in horsenettle ( Solanum carolinense L.) were investigated. The shoot emergence period in an undisturbed population was limited to a seven-week period from mid-April, and a little longer in tilled conditions. Detached roots showed very high shoot-sprouting ability under 15–30°C throughout the year. In shoot clipping experiments, new shoots sprouted only from the stem and not from the root when attached to shoots, whether above-ground or underground. On the contrary, new shoots sprouted from the roots when all parts of the shoots were clipped off. From these results, the limited shoot emergence period in horsenettle is thought to be initiated by temperatures necessary for sprouting and is ended by a growth correlation effect between early emerged and matured shoots.  相似文献   

‘过山香’香蕉多芽体的诱导及其体细胞胚的发生   总被引：7，自引：2，他引：7  

魏岳荣  黄学林  黄霞  李佳  肖望  李筱菊 《园艺学报》2005,32(3):414-419

 以我国重要香蕉种质‘过山香’ (AAB) 为材料, 研究了香蕉多芽体诱导、多芽体茎尖薄切片即分生组织性的表层结构物( scalp) 愈伤组织诱导和体细胞胚发生的合适条件。结果表明, 该品种单个不定芽茎尖在P4培养基(含BAP 100 μmol·L ^{- 1}和IAA 1 μmol·L ^{- 1} ) 中继代5个周期后可诱导获得类似花椰菜结构的多芽体。从30 μmol· m ^{- 2} ·s^{- 1}光强, 光/暗周期(16 h /8 h) 培养的多芽体所获得的scalp在添加2,4-D 5μmol·L ^{- 1}和Zeatin 1 μmol·L ^{- 1}的愈伤组织诱导培养基中黑暗培养, 45 d后愈伤组织诱导率可达97.6%。诱导20 d后黄色分生小球体类结节状愈伤组织开始发生, 90～120 d后在分生小球体局部可获得白色或浅黄色松散的胚性愈伤组织(诱导率为17.5% ) 。从胚性愈伤组织诱导的体细胞胚在成熟培养基上培养60 d后体胚萌发率和植株转化率分别为14.5%和11.1%。  相似文献