缺钾诱导早衰条件下应用嫁接技术研究根-冠互作对棉花下胚轴解剖结构的影响

缺钾诱导早衰条件下,根-冠互作对棉花叶片早衰的调节包括地上部主导型和根系主导型。本研究主要观察缺钾条件下2种根-冠互作类型单接穗单砧木(I型)和双接穗单砧木(Y型)嫁接接穗下胚轴的解剖结构,并判断其与下胚轴木质部中CTK和ABA的流量是否有关。结果表明,地上部主导型I型嫁接接穗下胚轴解剖结构与砧木品种更为相似,与其木质部CTK和ABA的流量主要受地上部调节不符;Y型嫁接2个不同品种接穗之间下胚轴解剖结构的差异与其木质部CTK和ABA流量的差异虽然具有相关性,但可能是一种伴生现象。根系主导型I型嫁接砧木对接穗的影响很大,但这与砧木对接穗下胚轴木质部CTK和ABA流量的调节可能也是一种伴生现象;Y型嫁接2个不同接穗之间下胚轴解剖结构差异较大,与二者之间CTK和ABA流量无显著差异的结果不符。因此,棉花叶片早衰2种根-冠互作类型接穗下胚轴解剖结构与其木质部中CTK和ABA的流量无关。此外,无论是地上部主导型还是根系主导型,2个品种自身嫁接的接穗下胚轴结构差异在Y型嫁接与I型嫁接中不一致,可能与Y型嫁接的2个接穗之间存在冠-冠互作有关。     

适用于低钾条件下棉花苗期根冠通讯研究的三种嫁接方法

为了满足棉花叶片衰老(以缺钾诱导)过程中根冠通讯研究的需要, 在营养液培养条件下探索了棉花子叶期至一叶期幼苗的单接穗单砧木嫁接、双接穗单砧木(Y型)和单接穗双砧木(A型)嫁接技术。通过研究营养液中钾浓度、砧木和接穗的苗龄配合、嫁接部位及砧木保留子叶对嫁接成活率的影响, 综合考虑嫁接成活率和成活后用缺钾诱导嫁接苗衰老的速度, 确定接穗单砧木嫁接和Y型嫁接的砧木均在不含钾的沙床中出苗后(萌发后3 d)转移至钾浓度为0.1 mmol L^-1(中度钾胁迫)的1/2改良Hoagland营养液中培养5 d至第1片真叶出现, 接穗在不含钾的沙床中出苗后(萌发后3 d)再生长2 d, 采用砧木留子叶法在子叶节处嫁接。A型嫁接的适宜条件和方法为砧木和接穗苗龄(第1片真叶刚出现)相同, 嫁接前的培养方法同Y型砧木, 嫁接部位在砧木子叶节下2~3 cm处。单接穗单砧木、Y型和A型嫁接的平均成活率分别可达到95%、85%和90%以上。     

不同砧木处理方法对3种橡胶树芽接苗生长的影响

为了缩小橡胶树芽接苗砧木芽对砧木养分的消耗,缩短接穗的待抽芽时间,减少抹芽用工,降低育苗成本,采用截砧和折砧2种砧木处理方法,对目前生产上常用的3种橡胶树芽接苗（小苗芽接袋苗、籽苗芽接袋苗、籽苗芽接杯苗）的砧木进行处理,比较分析这2种方法对橡胶树芽接苗砧木芽、接穗出芽及生长情况。结果表明：（1）折砧处理可极显著减少橡胶树芽接苗2~5次的抹芽次数及3.5~13倍的抹芽用工。（2）折砧处理可极显著提高橡胶树袋育苗10%~20%的抽芽率和成苗率,截砧处理可使籽苗芽接苗的苗木质量提高20%~45%。（3）培育橡胶树小苗芽接苗时,宜采用折砧方法处理砧木;培育籽苗芽接苗时,宜采用截砧方法处理砧木。     

甘蓝型油菜早熟性状QTL定位及候选基因筛选

目前对于油菜早熟的研究主要围绕开花期性状进行,虽然开花期与生育期呈显著正相关,但却并不完全一致。对于油菜开花后一系列生长发育进程相关性状的遗传研究和QTL定位鲜有报道。本研究以成熟期差异较大的2个油菜品种‘花前早’和‘Global’构建的DH群体为材料,对影响油菜全生育期的各个发育阶段(开花期、花期持续时间、角果期持续时间和全生育期等)进行表型调查和QTL定位分析。共检测到30个早熟相关性状QTL位点,其中开花期、花期持续时间、角果期持续时间和全生育期等分别检测到12、5、4和9个QTL位点,解释了5.8%~22.4%的表型方差。发现4、2和1个全生育期QTL置信区间分别与开花期、花期持续时间、角果期持续时间位点置信区间完全或部分重叠。筛选到29个可能与油菜早熟性状相关的候选基因,它们通过调控花期或籽粒发育等生长发育进程影响油菜早熟。因此,在早熟性状的研究中,可以同时从开花期和籽粒发育过程入手,不但有利于使熟期进一步提前,也可减缓早熟油菜品种过早开花导致的冬前低温寒潮天气的不利影响。     

Assessment of runner bean (Phaseolus coccineus L.) germplasm for tolerance to low temperature during early seedling growth

The runner bean requires moderately high temperatures for optimum germination and growth. Low temperature at sowing delays both germination and plant emergence, and can reduce establishment of beans planted early in the growing season. The objective of this work was to identify potential runner bean germplasm with tolerance to low temperature and to assess the role of this germplasm for production and breeding. Seeds of 33 runner bean accessions were germinated in a climate-controlled chamber at optimal (17°C-day/15°C-night) and at sub-optimal (14°C-day/8°C-night) temperature. The low temperature tolerance was evaluated on the basis of germination, earliness, ability to grow and vigor. Differences in agronomical characters were significant at low temperatures for germination, earliness, ability to grow and early vigor except for emergence score. The commercial cultivars Painted Lady Bi-color, Scarlet Emperor, the Rwanda cultivar NI-15c, and the Spanish cultivars PHA-0013, PHA-0133, PHA-0311, PHA-0664, and PHA-1025 had the best performance under cold conditions.     

砂培条件下橡胶树砧穗间矿质养分的积累与分布

在砂培条件下对橡胶树砧穗间几种矿物质养分的积累和分布情况进行研究。研究结果如下：（1）砂培后植株中N、P、K、Ca、Mg含量均有不同程度的增加,但在无外源养分供应条件下,随着接穗的生长,N、P、K、Mg含量增加幅度减小并影响植株正常生长。（2）外源矿质养分利用水平因不同生长阶段而异,N和Ca在第二蓬叶时才开始利用,K和Mg在第一蓬叶时大量利用,而此时P素的利用很少。（3）矿质养分在砧木不同部位和位置的含量水平和分布有明显的差异。韧皮部中累积较多的养分,而Mg主要分布在木质部上部,P主要分布在韧皮部下布。     

The influence of flowering time genes on environmental adaptability in European wheats

Summary In order to obtain high levels of environmental adaptability in wheat varieties it is essential they flower at times appropriate to particular environmental conditions. The influence of three distinct genetic systems that together determine time of flowering is reviewed here.Vernalization genes are seen to be particularly important to winter wheats for their direct or indirect effects on winter hardiness. Vernalization genes play a minor role in determining flowering time in autumn sown winter wheats but insensitivity is essential if spring sown wheats are to flower.Day length sensitive photoperiod genes play a major role in determining flowering time and adaptability of autumn sown wheats. Insensitivity can promote yield advantages of over 35% in Southern European environments. 15% in Central Europe and offers benefits even in the UK. At present only a single allele of Ppd1 appears to have been introduced into commercial European wheat varieties. The merits of alternative Ppd1 alleles or different loci are discussed.The influence of earliness per se genes that determine flowering time independently of environmental stimuli is less well documented than the effect of photoperiod and vernalization genes. It is likely that genes on chromosomes belonging to groups 2, 3, 4, 6 and 7 may act to modify flowering time independently of environmental stimuli probably by determining numbers of vegetative and floral primordia being initiated or the rate of initiation of the primordia. Earliness per se genes appear to be widespread in European wheats and play a significant role in determining the exact time plants flower.     

大豆嫁接体系中砧木或接穗保留叶片数对接穗生长发育的影响

以早熟品种黑河27为砧木,晚熟品种自贡冬豆为接穗,通过嫁接并结合去叶处理,创造砧木和接穗叶片数各不相同的嫁接体,观察砧木及接穗的叶片数目对接穗发育的效应,分析大豆叶片中可传导开花诱导物质和抑制物质的有无、作用方式及其对植株发育的影响。结果表明,在长日照(16 h)条件下,与黑河27嫁接,导致自贡冬豆在嫁接后第30天(出苗后第41天)开花,而自体嫁接的自贡冬豆在试验结束前(>120 d)仍未开花,说明在非诱导光照条件(长日照)下,早熟品种黑河27的叶片可产生可传导的开花促进物质,并通过嫁接传导至晚熟品种自贡冬豆的顶端分生组织,诱导其实现成花转变。砧木诱导接穗开花的效应大小与其所保留的叶片数目呈正比,证明上述可传导物质对大豆开花的促进作用存在剂量效应。接穗去叶可导致自身花期提前,花数增加,显示晚熟接穗的叶片在长日照下可产生开花抑制物质。接穗上的花朵和荚果数目与其保留叶片数呈反比,证明开花抑制物质阻止生殖器官的发育,且其作用也具有剂量效应。接穗去叶部位对其成花发育状态亦有一定影响。本文提出,在大豆生长发育过程中,叶片根据光周期信号的变化,调节开花促进物质和开花抑制物质的多少和比例,进而协调营养生长和生殖生长的进度,保证生命周期的完成。     

早果、矮化、抗逆苹果砧木Y系的选育研究

为选育具有本土适应性的苹果矮化砧木,以中国原生的种质资源——野生晋西北山定子为试材,通过田间观察和综合评价,以其实生苗为自根砧嫁接苹果品种,以早花、早果为筛选指标进行初选,以连续开花和结果性能、耐旱性、抗寒性、接穗品种果实品质为主次顺序筛选指标,进一步逐级筛选,进行复选,以八棱海棠为自根砧,复选出的植株自根砧萌蘖苗为中间砧嫁接苹果品种,以矮化性、植株生长势、连续开花和结果性能、耐旱性、抗寒性、接穗品种果实品质为主次顺序筛选指标逐级筛选,进行决选。结果表明,以初选出的砧木群体(定名为Y系)作为自根砧的嫁接植株,早花早果特性和连续开花结果能力极为突出,矮化性状明显,抗寒、抗旱性较强;以决选出的4个优系为中间砧的嫁接植株,除具有Y系嫁接植株基本特性外,果实品质较好。Y系是具有较强的矮化、开花结果、抗寒、抗旱性能的苹果砧木群体,具有很大的苹果矮化砧木选育潜力;4个优系的矮化、开花结果、耐旱、抗寒性能较强,其中,Y-1(原名Y-B030)为矮化砧木,Y-2(原名Y-B094)为极矮化砧木,Y-3(原名Y-B007)为半矮化砧木,均已通过区试及品种审定。     

Optimization of light/dark cycle in an extended photoperiod-based speed breeding protocol for grain legumes

The use of high-performing varieties could contribute to increase food legume production and meet the population demand. However, the long process of conventional breeding is a serious limitation that needs further acceleration of genetic improvement. Speed breeding based on extended photoperiod is one of the techniques that allows rapid generation turnover by accelerating the plant life cycle. The present study focused on optimizing the duration of extended photoperiod for lentil, chickpea and faba bean in a growth chamber with light-emitting diode (LED) light sources. Significant differences in growth rate, biomass production, phenology, physiology, plant injury and yield components were observed depending on light phase durations (22, 18 and 14 h). Twenty-two hours of light resulted in earlier flowering and maturity, but higher stress symptoms than the other two light treatments. However, vegetative development was almost normal with limited stress under 14 h of light, but late flowering and maturity. Interestingly, good plant establishment with limited stress and shorter vegetative cycle was observed under 18 h of light. Therefore, a photoperiod of 18 h of light/6 h of darkness could be advised for a rapid breeding protocol.     

不同接穗长度和栽种时间对杨梅嫁接成活率及生长量影响的研究

为提高杨梅嫁接成活率和接穗利用率,2014年开展了不同接穗长度、不同栽种时间对杨梅嫁接成活率和生长量影响的研究。结果表明,杨梅嫁接后6d、12d栽种的,5--6㎝短穗嫁接的成活率达87%和88%,略低于8-12㎝长穗嫁接的89%和90%,二者差异不极显著;嫁接后6d、12d栽种的成活达87%-90%,极显著高于嫁接后1d栽种的20.2%-21%。研究认为,在嫁接后遇下雨天气,根据天气情况,在接后6d-12d内选择晴天栽种,可显著提高成活率;在接穗紧缺时采用短穗嫁接,可大大提高接穗利用率。     

Effects of Timing of Drought Stress on Phenology, Yield and Yield Components of Short-duration Pigeonpea

Nine short-duration pigeonpea genotypes were given adequate soil moisture throughout growth or subjected to water stress during the late vegetative and flowering (stress 1), flowering and early pod development (stress 2), or podfill (stress 3) growth stages under field conditions. The stress 1 treatment had no significant effect on the time to flowering. No stress treatment affected maturity or inter-plant flowering synchronization. The interval from a newly opened flower to a mature pod was about 30 days for all genotypes, and was unchanged in plants that were recovenng from stress 1 or undergoing stress 2. Seed yield was reduced to the greatest extent by stress 2 (by 37 %) and not significantly affected by stress 3 for all genotypes. No consistent differences were found between determinate and indeterminate genotypes in the ability to maintain seed yield under both stress 1 and stress 2. The harvest index was significantly reduced (22 %) by stress 2 but not by stress 1. However, under each soil moisture treatment, genotypic differences for seed yield were associated largely with differences in total dry matter production (TDM). For all genotypes, the number of pods m^-2 was the only yield component significantly affected by the water stress treatments. The stability of other yield components should be fully exploited to improve the stability of seed yield under drought conditions (drought resistance). Possible characteristics which may improve the drought resistance of short-duration pigeonpea include the ability to maintain TDM, low flowering synchronization, small pod size with few seeds pod^-1, and large 100-seed mass.     

叶子花花期调控技术研究进展

(深圳市莲花山公园管理处,广东深圳 518026)     

砧穗苗龄对嫁接番茄生长、产量的影响

为研究砧穗苗龄对嫁接番茄生长及产量的影响,以‘金棚砧木1号’为砧木,‘金棚8号’为接穗,砧木苗龄为4~6叶,接穗苗龄3~5叶,采用二因素完全随机设计,分析不同砧穗苗龄对嫁接番茄嫁接苗成活率、嫁接苗生长指标、叶片色素含量及产量和果实品质的影响,并采用综合满意度法对砧穗苗龄嫁接组合进行综合评价。结果表明,砧穗苗龄共同影响着嫁接番茄苗的愈合、成活、生长及产量和品质,交互作用显著。接穗和砧木苗龄相近嫁接成活率较高,‘穗4/砧4’组合具有较高嫁接成活率。砧木苗龄对嫁接番茄植株生长发育、叶片色素含量及果实产量的影响较大,接穗苗龄对嫁接番茄果实品质的作用显著。较大苗龄砧木嫁接番茄植株杆茎粗壮,根系发达,地上、地下、全株干物质量明显增加,产量增加显著。采用满意度法综合评价番茄嫁接苗嫁接成活率、嫁接植株生长发育、产量及果实品质,发现接穗苗龄3~4叶、砧木苗龄6叶的番茄嫁接植株生长健壮,产量及果实品质显著提高,可作为番茄嫁接较适苗龄进行推广。     

橡胶树砧穗胶乳养分含量与产量的关系

为探讨橡胶树高产的机理,分析了不同产量水平橡胶树(PB86)砧木和接穗胶乳养分含量的差异。通过对干含、总固形物、硫醇、糖、无机磷、粗蛋白等的比较分析,结果表明,（1）橡胶树自身的砧木与接穗之间,除超高产橡胶树砧木中蔗糖、硫醇的含量极显著高于接穗外,其他养分含量在超高产、高产橡胶树自身的砧木与接穗之间差异并不显著,但一般单株橡胶树接穗胶乳中干胶含量、总固形物含量均极显著高于自身砧木。（2）不同产量水平的橡胶树之间,产量越高的橡胶树其砧木胶乳中各种养分的含量也越高,超高产橡胶树砧木中干含、总固形物、硫醇、糖的含量均极显著高于高产树和一般单株。（3）不同产量水平橡胶树接穗间硫醇、蔗糖、粗蛋白的含量差异均未达极显著水平。相对而言,与嫁接后橡胶树砧木与接穗之间的营养物质运输对橡胶树产量的影响相比,嫁接时优良砧木材料的选择更为重要。     

不同砧穗组合对红肉蜜柚树体和果实品质的影响

为研究张家界地区不同砧木类型对红肉蜜柚树体和果实品质的影响,以2 种砧木和4 种中间砧类型的红肉蜜柚为试材,对植株生长势、果实内在和外在品质进行测定和比较。结果表明,不同砧穗组合红肉蜜柚植株生长势表现出较大差异,其中酸柚砧和菊花芯柚中间砧组合株高最高,温州蜜柑中间砧组合株高最低;酸柚砧亲和性较好,枳砧亲和性较差,存在明显“大脚”现象;椪柑中间砧的接穗粗度明显大于中间砧,其他组合均略小。不同砧穗组合对红肉蜜柚果实品质有明显影响。外在品质方面,酸柚砧和椪柑、菊花芯柚中间砧组合果实体积明显大,单果重也明显高;果实中心柱大小与果实大小有较高相关性;砧穗组合类型对果形指数影响不大。内在品质方面,椪柑中间砧组合果实可溶性固形物含量明显 低,而酸柚砧和菊花芯柚中间砧组合果实可滴定酸含量明显高于其他组合。以酸柚为砧木,树势旺盛、果实体积大、单果重更高,虽然可滴定酸稍高,但是可溶性固形物含量也不低,同时不存在与接穗品种不亲和的现象,所以酸柚的综合表现比较均衡,是目前比较适合用作红肉蜜柚砧木的类型。本研究为张家界地区发展红肉蜜柚产业,提高产量、改善品质提供了参考。     

Effects of irradiance and juvenility on the selection of chrysanthemums

Summary Chrysanthemum morifolium seedlings and cuttings from those seedlings were grown to flowering at 17°C, short days (8 h) and two levels of irradiance (10 and 30 W m^–2). The cuttings flowered more readily than the seedlings at both irradiances, Especially at 10 W m^-2 many seedlings remained vegetative. The delay in flowering of the seedlings was accompanied by a higher number of leaves produced before flowering.The number of leaves produced by the seedling in excess of the number of leaves produced by the cutting from that seedling varied considerably between genotypes. The correlations between seedlings and the corresponding cuttings for days to flowering and number of leaves were low but generally significant.It is concluded that cuttings are preferred over seedlings in breeding programmes that aim at developing chrysanthemums for low light winter production.     

A new dominant earliness character of CMS line Zaoxian A and its application value in rice (Oryza sativa L.)

Summary A distant cross between a maintainer Zhenshan 97B and an early maturing F₂ palnt of O. longistaminata x O. rufipogon was made in 1985, and a new CMS line Zaoxian A was bred in 1989 through continuous backcross of new maintainer plants derived from the distant cross to the leading CMS line Zhenshan 97A. Several experiments were carried out in Sichuan during 1990–1992, to analyze the inheritance of earliness of Zaoxian A and its application value to hybrid rice production. The results showed that Zaoxian A was as early-maturing as Zhenshan 97A, the earliness of Zaoxian A was incompletely dominant to the lateness of restorer lines, and was different from the earliness of Zhenshan 97A which was suppressed by the lateness of restorer lines. The F₁ hybrids between Zaoxian A and late maturing restorers combined the early maturity and high yielding capacity, and significantly outyielded the provincial and national checks with same or longer growth duration, because the larger genetic distance between early and late maturing ecotypes remained unchanged and the new earliness could express in F₁ generation. Therefore, the new dominant earliness character of Zaoxian A could enhance the regional and seasonal adaptability of rice. It is also valuable to hybrid rice production and the formation of new cropping systems with high yielding capacity and high economical profit.     

Juvenile phase and growth of apple and pear seedlings

It was investigated whether and to what extent the duration of the juvenile phase of pear and apple seedlings is related to their vegetative growth. The juvenile phase was defined as the period in years that the seedling remains vegetative; the trunk diameter served as a measure of vegetative vigour. The following observations were made:

1. 1)

   A significant negative correlation exists between the duration of the juvenile phase and the vigour of the seedling (as measured by trunk diameter).

2. 2)

   Environmental conditions with respect to weather, soil and cultural practices which promote or restrict growth, tend to shorten or lengthen the juvenile phase accordingly by their influence on the time required for the attainment of a certain minimum size which at least partly determines the attainment of the flowering condition.

3. 3)

   The weak rootstock M. IX significantly accelerated the onset of flowering of apple seedlings by about 1 1/2 years; this rootstock appears to combine a retarding effect on growth with a specific influence on flowering.

     

Component analysis of plant dry matter production: a basis for selection of breeding parents as illustrated in carnation

Summary Improvement of dry matter production in the vegetative phase is a breeding objective in many crops, especially where whole plants or parts of plants in the vegetative phase constitute the commercial product. Dry matter production is a complex process and plant dry weight, as measured at a given date, is a complex character, of which initial weight of planting material and mean relative growth rate over the period of growth are the major components.The primary objective of the present paper is to demonstrate how a method of component analysis proposed by Sparnaaij and Bos can be used to facilitate breeding for a high rate of vegetative growth. The procedure is illustrated by data from a study of variation in forcing ability among 13 carnation cultivars. It involves a detailed analysis of mean relative growth rate over the period of vegetative growth, including components derived from observations on net rate of photosynthesis and dark respiration.It is shown how component analysis can be used (a) to quantify the relative contribution of initial plant weight and of mean relative growth rate and its components to the genetic variation in plant dry weight, thus allowing a judicious choice of selection criteria for breeding parents, and (b) to predict mean plant dry weight of F₁ hybrids obtained by crossing these parent genotypes, thus facilitating the choice of crosses to be made.