马铃薯不同芽龄种薯生理效应的研究

马铃薯种薯芽龄(种薯萌芽时间)影响种薯的生理年龄。根据不同芽龄种薯芽条形态解剖,种薯生理变化及植株形态生理,产量形成等方面的研究。结果表明,芽条发育程度,芽生长锥分化程度与芽龄大小成正相关,种薯内的生理变化、植株生长发育、生理兴衰变化、产量形成等与种薯芽条发育程度,特别是芽生长锥分化程度呈显著相关。芽条生长锥分化程度相近的种薯,具有相近的生理效应。     

不同种茎处理对甘蔗萌芽和幼苗生长的影响

以不同部位、不同芽数和不同质量的甘蔗种茎为材料,分析不同种茎来源对甘蔗萌芽和幼苗生长的影响。结果表明：中部种茎萌芽出苗及幼苗生长表现最好,萌芽率和苗高分别为72.81%和46.33 cm;单芽茎的萌芽率较低,苗较矮,而三芽茎、四芽茎和多芽茎的萌芽率和苗高差异不明显。正常种茎的萌芽率与倒伏种茎的差异不显著,与绵蚜危害种茎、螟虫危害种茎和黑穗病危害种茎的差异显著;正常种茎苗高与螟虫危害种茎的差异不显著,与绵蚜危害种茎、倒伏种茎和黑穗病危害种茎的差异显著;而黑穗病危害种茎芽萌发长成的植株只有3.82%为正常植株,其他均为黑穗苗。结果说明生产上选健康的甘蔗中部或梢部茎留种,以双芽段、三芽段、四芽段或多芽段种茎种植有利于甘蔗萌芽和幼苗生长。     

马铃薯种薯芽条根原基的发生与发育过程的解剖观察

对种薯芽条根原基的切片观察发现:根原基发生在芽条上各侧芽原基附近,由靠近形成层的一团薄壁细胞再分化形成,属内生源;每节约有3～6个根原基,成对地分布在侧芽原基的上、中、下3个部位,中部的1对根原基先发生且较长;芽条上的根原基一般依由基向顶的顺序发生,但基部1～2节的发生较晚,尤其是在用高浓度GA处理切块的芽条中;基部几节的根原基往往在栽种到大田后才发生,芽条越长根原基的数目越多、越长,当长度大于2cm时,根原基已接近或突破表皮,这是催大芽可提早出苗的基础;根原基的分化和伸长可能与芽条生长速度有关。     

马铃薯试管薯发育机理的研究──温度对试管薯形成的影响

以“中薯３号”脱毒试管苗为材料，研究诱导温度对试管薯形成及发育的影响．结果表明：在全黑暗诱导条件下，试管薯形成的最适温度为１５～２０℃．对试管薯形成大小及著重而言，温度效应高于外源诱导剂．温度对平均单瓶结薯数影响不显著．     

块茎比重和结薯节对马铃薯幼芽生长的影响

据Svensson(1966)报道,马铃薯生长和产量的变化主要取决于每一批种薯的特性。他认为,一批之中种薯间比重的差异代表着不同的化学组成和生理年龄。种薯的生理年龄是根据可见芽的发育程度来确定的,它能影响植株的茎数、产量和熱期。因此种薯比重对幼芽发育的影响既可改变密度和块茎的成熟度,     

橡胶树花芽不同发育阶段秋水仙素诱导花序变异效果的研究

橡胶树混合芽（即橡胶树“花芽”）发育不同联合会的形态结构观察及秋水仙素对其染色体数诱导加倍的研究结果表明：长１．５～３．９ｍｍ的萌动混合芽处于圆锥花序的分化初期，其生长锥下方刚形成花序的一级分枝原基，细胞分裂量较大，在该阶段用０．２５％秋水向素溶液进行染色体数加倍处理，较易获得整体加倍的变异花序。     

马铃薯种薯在高温下萌芽的生物学效应

本试验以晋薯2号品种的带毒及无毒种薯为材料,在萌芽期间进行高温(25～28℃)贮藏处理,以低温(4～7℃)处理作为对照,研究种薯在高温条件下萌芽对后代植株生长、生理及产量的影响,探讨种薯生理年龄的衡量指标以及萌芽高温和病毒在马铃薯退化中的作用。     

脱毒马铃薯扩繁技术初探

本试验以早熟品种东农３０３、中熟品种系薯１号和晚熟品种晋薯７号为试验材料，采用Ｌ１２（４×３￣２）正交试验法，分室内和室外两组同时进行试验，结果表明，出芽天数随着温度的上升而减少；大薯块出芽数极显著高于中小薯块；出芽数则随着掰芽次数的增加而减少；系薯１号的出芽数明显高于晋薯７号，与东农３０３差异不显著．产量结果表明，主因素为品种；其次为薯块大小；掰芽次数间差异不显著；母薯则极显著高于掰芽次数．综合结果分析，脱毒马铃薯掰芽扩繁是一项节省种薯，提高繁殖系数的有效措施；以选择适宜当地种植的高产高效和大薯块掰芽为好；三次掰芽扩繁移栽和母薯直播是可行的马铃薯扩繁技术措施．     

温度和光照对香蕉组培苗生长和增殖的影响

以“巴西”香蕉为材料,在人工气候箱条件下,研究不同温度（16,19,22,25,28,31,34 ℃）及不同光照（1 000,1 500,3 000,5 000,8 000 lx）对香蕉组培苗增殖和生根的影响。结果表明,温度对香蕉分化芽的增殖和生根均有极显著影响;光照主要影响分化芽和生根苗的长势,而对香蕉分化芽的增殖和生根没有显著影响;温度与光照的互作对香蕉分化芽的增殖没有显著影响,而对分化芽的长势和生根均有显著的影响。31 ℃时香 蕉分化芽的倍增率和生根率均达到最大,分别为 3.07 和 0.98。增殖培养阶段香蕉分化芽的叶绿素含量低于生根培养阶段。当温度在 25～31 ℃之间、光照在 1 000～3 000 lx 之间时,叶绿素含量均相对较高。高、低温及强光照下叶绿素含量均相对较低。     

甘蔗引进品种宿根蔗遭受冰冻雨雪天气危害后萌芽发株表现

甘蔗是喜温作物,其宿根蔗萌芽发株需要较高的温度条件,温度过低就会抑制根部蔗芽的萌发,影响宿根蔗的发株.宿甘蔗萌芽发株较适宜的温度一般在25-32℃之间,20℃以下萌芽发株缓慢,低于13℃蔗芽很难萌发,休眠芽在一1℃以下、萌动芽在0℃以下被冻死.     

大田越冬水稻种子的筛选鉴定

连续阴雨与早春低温是影响我国南方水稻生产的主要不利气候因素,常导致水稻烂芽和烂种。本研究通过在自然条件下筛选大田中越冬后而能够在翌年发芽成长为植株的方式,以期获得成苗率高、烂芽烂种率低的种质资源。结果表明,172份种质在自然条件下经历冬季后,绝大部分种质的种子腐烂,仅Kasalath和日本晴种子在大田越冬后能发芽生长。这两种常规水稻种子大田越冬特性的发掘,将为培育降低烂芽烂种率的优良品种提供宝贵种质资源。     

The effects of (S)-(+)-carvone treatments on seed potato tuber dormancy and sprouting

Summary Potato seed tubers may suffer from premature sprouting during storage, thus limiting their suitability for cultivation. Commonly used sprout suppressant treatments negatively affect but viability and therefore a reliable method to inhibit bud development must still be found for seed tubers. The monoterpene carvone ((S)-(+)-carvone) was tested in small scale experiments. The vapour of this compound fully inhibited bud growth of tubers cv. Monalisa stored at 23°C without affecting bud viability throughout 6 months of treatment. The most effective range of carvone vapour concentrations was between 0.34 and 1.06 μmol mol⁻¹. With these qualities we can expect carvone to become a suitable sprout suppressant for seed tubers.     

Techniques for using sprouts for potato production in the tropics

A series of experiments were conducted in Vietnam to develop a system whereby detached sprouts from physiologically old green sprouted seed tubers could be used to grow potatoes. Three node segments from the mid or basal portion of the detached sprout produced the greatest percentage of shoots and roots. Growth was best in a medium of equal parts of sub-soil, pig manure and brick kiln ash. Sprout cuttings produced plantlets ready for transplanting in 14–20 days with mean daily temperatures of 22 to 24°C. When transplanted in mid-November, yields from sprout cuttings in field experiments were 10 to 18 t/ha which were 33% lower than from healthy seed tubers but more than the national average yield using degenerated seed tubers. Tubers produced by plants grown from sprout stored well and gave good yields when replanted the following year. Requests for reprints to International Potato Center, Box 933, Manila, Philippines.     

芝麻干物质积累和分配研究初报

豫芝4号芝麻现蕾前积蓄的光合产物对产量贡献很小。现蕾至终花约40天内是芝麻产量形成的关键时期。这一时期营养生长和生殖生长竞争激烈,对外界环境敏感,栽培措施应以调节干物质分配流向为主,争取早发、稳长。封顶后,全株及蒴果干物质积累仍维持较高水平,延长后期光合器官功能,防止早衰,将有利于减少秕粒,提高千粒重。     

Comparative performance of three small seed tuber sizes and standard size seed tubers planted at similar stem densities

Summary Small seed tubers of 1–5 g, 5–10 g and 10–20 g were planted at the same sprout densities as standard size seed tubers of 40–60 g in order to give similar stem densities. Early ground cover by foliage, total yield, and yield of tubers >45 mm were consistently greater in plots planted with larger seed tubers. The effect of seed tuber size on yield and tuber number per stem varied between years but 1–5 g seed tubers always gave lower yields per stem than larger seed tubers. Reducing the spacing between rows from 90 cm to 60 cm and maintaining the same sprout density was more effective in increasing yields from small seed tubers than increasing sprout density from 20 to 40 sprouts per m² by reducing plant spacing within the row.     

A comparison of some methods for detecting potato leaf roll virus in potato tubers in Israel

Summary The results obtained by four methods for detecting PLRV in potato tubers grown in Israel were compared with the results obtained by aphid transmission to test plants. The correlation coefficients for potatoes lifted in July (seed for autumn) and September (seed for spring) were: Igel-Lange test, 0.18 and 0.25; datura grafting with tuber sprouts, 0.71 and 0.63; aphid transmission from sprouts to test plants, 0.89 and 0.81; and visual assessment in the Florida test (for spring seed), Up-to-Date 0.58, Blanka 0.67 and Désirée 0.33. The Igel-Lange test proved unreliable; datura grafting is time consuming and PLRV symptoms were similar to reactions ofDatura stramonium to wounding and to stress. The results of the Florida test were somewhat variable and were obtained too late. The sprout test was deemed the most suitable as it is accurate and the results can be obtained within two months. Contribution No 156-E, 1979 series, Volcani Center.     

Inter-stem and inter-tuber competition in potatoes

Summary Seed pieces of varying size and bearing different numbers of uniform growing sprouts were planted in specific combinations. Sequential harvests were made and the growth of the plants followed. There appeared to be competition between emerging sprouts for nutrients and water from the soil. This competition influenced the number of stems produced per sprout and the size attained by these stems. There was no effect of size of the seed piece on the apparent time to tuber initiation. A constant number of tubers were formed per stem despite large variations in stem size, but the final weight of tubers per stem was lower the greater the number of stems per hill. The number of tubers larger than 2| inches (5.7 cm) remained constant over the whole range of stem numbers per hill and the mean weights of tubers in the two size categories larger than 1| inches (3.2 cm) remained constant after the second harvest. These results suggest that only a few of the tubers in each hill were growing rapidly at any one time. There was no effect of cutting the seed tubers on any aspect of the growth of potatoes that was measured which could not be attributed to an effect on either the size of the seed piece or on the number of sprouts per seed piece.