沙田柚在不同枳选系砧木上的早期表现

比较了4个枳选系作沙田柚砧木的早期表现。结果表明,以不同枳选系作砧的沙田柚在树冠生长量、早结性等方面有差异。以小叶小花类型枳作砧木的,树冠小,结果早,以小叶大花类型枳作砧木的,树冠大小中等,但结果较迟。     

缺铁胁迫下4种野生梨砧木介质pH值及根系Fe~(3+)还原酶活性的变化

以川梨、砂梨、豆梨和杜梨为材料,研究了在缺铁胁迫下培养介质的pH值和根系Fe3+还原酶活性的变化。结果表明,缺铁胁迫使4种砧木的介质pH值于处理的第2天就迅速降低,并且一直低于低铁和正常供铁处理;而低铁处理下,介质pH值在最初几天内反而高于正常处理,至4～5d之后才逐渐低于正常供铁处理;同时,NH4+-N对降低介质pH值和缓解缺铁症状有利。4种砧木的根系Fe3+还原酶活性都随供铁浓度的增加而不同程度的增大:无铁处理下,砂梨根系Fe3+的还原能力最小、杜梨最大;而在低铁和正常供铁条件下,砂梨和川梨的还原能力最强,杜梨次之,豆梨最小。还原酶大小与症状表现之间具有一致性。     

Evaluation of Olive Cultivars for Resistance to Verticillium dahliae

Resistance of 23 important olive cultivars to Verticillium dahliae has been evaluated in four experiments under controlled conditions. Nine-month-old nursery olive plants were inoculated with a cotton non-defoliating (ND) (V4) or a cotton defoliating (D) (V117) isolate of V. dahliae. Resistance was evaluated by assessing symptom severity using a 0–4 rating scale and estimating the area under disease progress curves. The percentage of plants killed and of those which recovered from the disease were used as additional parameters for including a particular cultivar into a defined category. Most of the evaluated cultivars were susceptible, although at different levels, to both isolates of V. dahliae. All cultivars were more susceptible to the D pathotype than to the ND one. A group of 11 cultivars, including several important Spanish cultivars, were susceptible or extremely susceptible to both pathotypes of V. dahliae. A second group showed differences of resistance depending on the pathotype used. They were susceptible or extremely susceptible to the D pathotype but resistant or moderately susceptible to the ND one. Finally, 'Frantoio', 'Oblonga' and 'Empeltre' were moderately susceptible to the D isolate of V. dahliae and resistant to the ND one. The resistance of 'Empeltre' was evident by the plant ability to recover from infection with either isolates. 'Empeltre' is considered to be a valuable cultivar for inclusion in breeding programmes for resistance to Verticillium wilt.     

甜樱桃不同砧穗组合成花调控关键基因表达差异研究

为了研究甜樱桃(Prunus avium)成花调控关键基因在不同砧穗组合中表达差异,以甜樱桃‘艳阳’(Sunburst)为接穗,‘ZY-1’(P.cerasus)、马哈利(P.mahaleb)和‘兰丁2号’(P.avium × P.pseudocerasus)为砧木的嫁接组合为试材,调查统计4年干龄不同砧穗组合的总花芽量及开花情况;克隆甜樱桃成花调控网络中EARLY FLOWERING 3(ELF3)、CONSTANS(CO)、FLOWERING LOCUS T(FT)等9个关键作用基因,并利用实时荧光定量PCR对不同砧穗组合接穗的幼叶、叶芽、成龄叶、花芽、叶芽附近叶片叶柄及花芽附近叶片叶柄中这些基因的表达量鉴定。结果显示,艳阳/ZY-1、艳阳/马哈利和艳阳/兰丁2号组合的平均单株花芽量分别为279、288和317朵,不存在明显差异,但不同组合的花期却明显不同,当艳阳/马哈利有72%花芽处于开放期时,艳阳/兰丁2号的花开放比例只有7%,艳阳/ZY-1的花开放比例为49%;此外,PaELF3、PaCO、PaFT等9个成花关键基因,在同一时期不同砧穗组合的接穗组织中表达量存在差异,其中PaAP1在不同砧穗组合的花芽中表达模式与花期规律一致,表明PaAP1与樱桃花期调控密切相关。     

缺硼条件下两种不同砧木“纽荷尔”脐橙矿质元素含量变化的比较

采用溶液培养试验,研究了缺硼对两种不同砧木纽荷尔脐橙硼、锌、钙、镁和钾元素含量变化。结果表明,缺硼显著降低了枳壳砧木纽荷尔脐橙体内硼含量而对锌含量影响不大; 相反,缺硼对枳橙砧木脐橙体内硼含量的影响不是很大,而显著降低了其叶片中锌的含量。这可能是缺硼条件下枳壳砧木脐橙容易出现缺硼症状,而枳橙砧木脐橙容易出现缺锌症状的原因之一。与对照相比,缺硼处理的枳壳砧木脐橙叶的钙含量明显增加; 而根的钾含量明显高于枳橙砧木橙根。这些结果与枳壳砧木脐橙对硼更敏感有一定的关系。缺硼对镁含量的影响两种砧木间基本没有差异。     

Sap flow in ‘Hass’ avocado trees on two clonal rootstocks in relation to xylem anatomy

The rates of sap flow and xylem vessel features were studied in two-year-old nongrafted and grafted avocado (Persea americana Mill.) trees. Daily sap flow rates were measured with heat and balance stem gauges in clonal Duke 7 (D7) and Toro Canyon (TC) trees and ‘Hass’ clonal scions grafted onto clonal D7 (H/D7) and TC (H/TC) rootstocks. Vessel features as size, number and total vessel area were determined histologically in the stem of the scion and rootstock and the roots of the grafted trees. Significant differences in the sap flow rate were found among the rootstocks, where D7 had a 29% higher sap flow rate than did TC (grafted and nongrafted trees). There were no differences among xylem vessel features in the stems of any of the varieties. However in the roots, D7 had wider and fewer vessels then TC do. Also, D7 had a 19% higher total vessel area than TC. These results suggest that the differences in water consumption of ‘Hass’ on different rootstocks may be associated with differences in the efficiency of the roots to absorb water across conductive tissue which may be linked to differences in the area of xylem vessels in the root.     

Screening of cold-resistant seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of eastern Gansu province,China, as rootstocks

Seedlings of a Chinese wild grape (Vitis piasezkii Maxim var. pagnucii) native to loess plateau of Eastern Gansu province, China, were evaluated to screen cold-resistant rootstocks in Lanzhou area. After 14-year investigation two selections of LDP-191and LDP-294 were screened as rootstocks for two table grape cultivars, ‘Fujiminori’ and ‘Red Globe’, respectively. The two graft unions demonstrated very high cold-resistance as well as good graft compatibility. Furthermore, they could survive through low temperatures in winter without soil coverage together with good fruit quality of the cultivars grafted.     

黄瓜嫁接砧木用南瓜新品种‘绿洲天使’

 ‘绿洲天使’是由引自日本的南瓜自交系‘98-6-2-1-3-1-2-2’与引自印度的南瓜自交系‘99-12-2-4-1-1-3’配制而成的黄瓜砧木用南瓜新品种。该品种嫁接亲和力好, 嫁接苗抗枯萎病能力强, 耐低温弱光能力好, 产量高, 嫁接黄瓜品质优良, 适宜全国各地日光温室、大棚及露地黄瓜嫁接栽培。     

半根供铁对苹果砧木幼苗生长的影响

利用分根技术在水培条件下研究了半根供铁对苹果砧木幼苗生长的影响。结果表明,一半根系供铁不仅未影响植株对铁营养的需求,甚至在处理初期植株的铁吸收总量和铁吸收速率还略有提高。一半根系供铁苹果砧木小金海堂和山定子叶片活性铁质量分数均未降低,而且与对照相比无叶片黄化的现象。因此,通过半根供铁的方式来改善苹果砧木幼苗的生长,为进一步研究砧木缺铁适应性反应的调控部位打下基础,也为今后缺铁的矫正和提高铁素利用效率提供了一条新的思路。     

有机态和无机态硼对柑橘枳橙砧木生长及生理的影响

以柑橘枳橙[Citrus siinensis(L.)Osb.×Poncirus trifoliata(L.)Raf.]砧木为试验材料,采用水培方式,研究有机态山梨醇—硼和无机态硼酸对其生长及各种生理指标的影响。两种形态硼都能增加砧木幼苗各部位的干、鲜质量和株高;有机态山梨醇—硼对地下部生长的促进作用尤为明显。有机态山梨醇—硼比无机态硼酸更易于向叶片等地上部位转运,有机态山梨醇—硼处理根和茎中的硼含量与无机态硼酸处理没有显著差异,但叶片中的硼含量与硼积累量均显著高于无机态硼酸处理,叶片占总硼含量的比例也显著高于无机态硼酸处理。有机态山梨醇—硼处理各部位钾、钙、镁元素含量高于对照,而无机态硼酸处理各部位元素含量则比有机态山梨醇—硼处理高。缺硼易导致叶片中糖类物质的积累,有机态山梨醇—硼比无机态硼酸能更有效地促进叶片中多糖物质的转运,有机态山梨醇—硼处理可溶性糖含量比对照和无机态硼酸处理分别降低26.3%和11.8%,淀粉含量分别降低43.5%和26.1%。在提高枳橙砧木叶片抗逆能力方面,有机态山梨醇—硼效果优于无机态硼酸,两种硼类型处理叶片中脯氨酸和伤害率均显著低于对照,有机态山梨醇—硼和无机态硼酸分别降低了20.6%和19.6%,有机态山梨醇—硼和无机态硼酸处理伤害率降低了13.3%和16.5%,有机态山梨醇—硼处理叶片中丙二醛含量显著低于无机态硼酸处理19.4%。有机态硼对改善枳橙砧木根系的生长发育的作用效果优于无机态硼酸;能有效降低叶片中碳水化合物的含量,有利于光合作用产物顺利转移;而在减少叶片有害物质的积累、保护质膜方面,有机态与无机态硼有同样的效果。