不同苜蓿品种对叶片愈伤组织诱导及植株再生的影响

以7个苜蓿品种叶片为外植体,采用3种诱导培养基、5种分化培养基,共15个组合,研究了不同品种间愈伤组织诱导及植株再生的差异。结果表明,不同苜蓿品种间植株再生率差异显著,超级13R在7个苜蓿品种中表现最佳。     

拮抗细菌菌株B5423-R和Pf7-14在水稻叶片上的定殖及其对土著细菌群体的影响

拮抗细菌菌株Bacillus subtilisB5423和Pseudomonas fluorescensPf 7-14能显著地抑制水稻纹枯病。在温室条件下,通过播种、叶片接种纹枯病菌Rhizoctonia solani,以及在水稻分蘖盛期喷雾菌株B5423-R(B5423的利福平抗性突变体)和Pf 7-14(天然的抗萘啶酮酸菌株)的细菌悬浮液,并通过定期取样、平板系列稀释法回收,监测了菌株B5423-R、Pf 7-14和土著细菌群体在水稻健叶和纹枯病叶上的种群动态。结果表明:在病斑叶片片段(病斑面积占70%~90%),在应用1~7 d后,菌株Pf 7-14的平均群体数量比在相同面积的健康叶片片段上显著性地高3~10倍,而菌株B5423-R的数量比在健康叶片片段上显著性地高12~50倍;土著细菌群体数量在病斑叶片上是健康叶片上的50~60倍。这些结果表明纹枯病病斑大大促进了土著细菌群体和引入的生防细菌的生长,且土著细菌群体和引入的生防细菌在营养和空间上是相互竞争的。     

Seasonal Changes of Mineral Nutrients in Fruit and Leaves of ‘Newhall’ and ‘Skagg's Bonanza’ Navel Oranges

In southern Jiangxi province of China, ‘Newhall’(Citrus sinensis Osbeck) navel orange presented a conspicuous symptom of boron (B) deficiency in mature leaves, whereas B deficiency symptoms were not manifested on ‘Skagg's Bonanza’(C. sinensis Osbeck) navel orange. In this study, changes in concentrations of B, calcium (Ca), potassium (K), magnesium (Mg), manganese (Mn), and zinc (Zn) were comparatively investigated in the structural parts of the fruit (rind and pulp) and leaves (old leaves from last season and spring-flush leaves from current year) of ‘Newhall’ and ‘Skagg's Bonanza’ navel orange during the growing season. Two peaks of B concentrations were observed in the rind of the two cultivars during fruitlet growth and fruit enlargement, respectively. Boron concentrations were relatively high in the rind during fruitlet growth, and then decreased in both rind and pulp, whereas, during middle and late fruit enlargement significant increases were found for B in both rind and pulp of the two cultivars. Boron concentrations in old leaves of ‘Newhall’ decreased progressively and remained relatively low, whereas that of ‘Skagg's Bonanza’ was relatively high and changed slightly as the season progresses. Both Ca and K concentrations were above the critical threshold values, while their dynamics were reverse to that of B in fruit and leaves during certain times. Old leaf Mg concentrations of samples at 140 days after full bloom from the two cultivars and spring-flush leaves from ‘Newhall’ were below the threshold limit for sufficiency. In addition, Mg in old leaves was much lower from ‘Newhall’ than from ‘Skagg's Bonanza’. Spring-flush leaf concentrations of Mn and Zn and Mn concentrations in old leaves from ‘Newhall’ were relatively lacking during middle and late season, which accelerated the occurrence of B deficiency symptoms on mature leaves of ‘Newhall.’     

三个葡萄品种叶片中激素变化与抗寒性关系的研究

以贝达（抗寒性较强）、赤霞珠（抗寒性中）和梅鹿辄（抗寒性较弱）3个葡萄品种的1 a生枝条为材料,测定不同低温胁迫（-15、5℃）下叶片中4种内源激素ABA、IAA、GA、iPA含量及比值的变化。结果表明：低温条件下,3个葡萄品种叶片中ABA呈现先升高后降低的趋势,而IAA、GA、iPA则显示出先降低后有所升高的变化;ABA与IAA、GA、iPA的比值总体表现出先升高后降低的趋势,并且其变化数值与温度呈负相关。抗寒性强的品种贝达叶片中ABA/GA、ABA/IAA均大于抗寒性差的品种梅鹿辄,其中ABA/GA和ABA/IAA的变化与抗寒性关系最为密切。据此推断,ABA/GA和ABA/IAA可以作为判断葡萄品种抗寒性的指标。     

桃叶片再生不定芽的研究

以桃栽培品种曙光、金童5号和甜桃王试管苗叶片为外植体,研究了基本培养基、植物生长调节剂种类及质量浓度组合、基因型和试管苗继代次数等因素对叶片再生的影响。结果表明,适宜暗培养的培养基为LP+1.5mg·L-1TDZ+0.15mg·L-1NAA;光培养基为LP+0.5mg·L-1TDZ+0.3mg·L-1KT+0.3mg·L-1NAA和LP+0.6mg·L-1TDZ+0.3mg·L-1KT+0.4mg·L-12,4-D;金童5号和曙光具有较强的再生能力,再生率分别为21.8%和14.5%;曙光和金童5号试管苗继代第1～11次叶片的再生能力与继代前3次愈伤组织相比形成率较高;曙光再生苗在培养基1/2MS+0.5mg·L-1NAA上生根率为100%,平均生根条数为7.9。     

壤质土叶面喷施不同养分对强筋小麦产量和蛋白质组分的影响

在壤质土条件下,不同养分叶面喷施对强筋小麦的株高、成穗数影响不显著;叶面喷洒0.1%MnSO4、0.05%(NH 4)2M oO2和0.3%KH 2PO4、2%CO(NH 2)2等能提高强筋小麦的千粒重和产量。喷洒2%CO(NH 2)2和0.1%M nSO4有利于蛋白质和蛋白组分的提高。     

利用组织培养技术向普通小麦导入簇毛麦抗白粉病基因的研究

 对硬粒小麦（T.durum）-簇毛麦（H.villosa）杂种幼胚和F#-1幼穗诱导的愈伤组织进行秋水仙素处理获得硬-簇双二倍体TH1，TH1W，TH2W，TH3，TH3W。平均加倍率为78.8%,最高为94.1%。通过与普通小麦（T.aestivum）回交，幼胚和花药培养，得到了6D/6V异代换系94G22-1，94G25-1，94G32-1，94G33-1。谷草转氨酶（GOT）和酯酶（EST）同工酶可作为这些材料的生化标记。RAPD分析中，引物OPAN3可作为其分子标记引物。     

墨旱莲叶水提取物止血活性初探

[目的]探讨墨旱莲叶水提取物的止血和促凝血活性,为中草药在止血方面的应用提供依据。[方法]将不同剂量的墨旱莲提取物溶液与抗凝兔血混合,测定凝血时间。[结果]墨旱莲叶提取物为0.5%的最适浓度时具有最强促凝血活性,凝血时间为16 s,凝血时间缩短率为99.6%。[结论]墨旱莲叶水提取物有显著的止血和促凝血活性,具有较高的开发利用价值。     

7个梨主栽品种生长季钙含量的动态变化

缺钙会引起许多果实生理性病害。为给梨树合理补钙提供理论依据,以7个梨主栽品种为试材,研究了其叶片、果实和新梢钙含量的动态变化规律。结果表明：随着梨的生长发育,参试品种的叶片和新梢钙含量均大体呈增加趋势,果实钙含量呈逐渐降低趋势（其中幼果期至果实成熟前期降速最快）,且同一品种幼嫩器官与成熟器官的钙含量差异均达到了显著水平,同一发育时期相同器官钙含量最大值与最小值的差异也达到了显著水平。钙含量最高的器官是叶片,其次是新梢,果实钙含量最低。不同梨品种的钙素营养水平存在差异,其中各器官发育末期的钙含量,均以鸭梨最高,黄冠和大南果较低。     

几种杀虫剂对小麦旗叶光合及叶绿素荧光特性的影响

为给小麦优质高效安全生产中科学使用杀虫剂提供理论和技术依据,以弱筋小麦扬麦13、强筋小麦烟农19为材料,在开花末期分别喷施推荐、3倍、6倍剂量的阿维菌素、毒死蜱、吡虫啉、乐果4种杀虫剂,研究其对小麦旗叶光合及叶绿素荧光特性的影响.结果表明,杀虫剂处理会改变小麦旗叶的SPAD值、光合速率及叶绿素荧光特性,且剂量越高影响越明显;不同类型杀虫剂对小麦光合速率及荧光特性的影响程度不同,影响较大的杀虫剂是吡虫啉和乐果,其次是毒死蜱,最后是阿维菌素;不同小麦品种对杀虫剂的耐受性不同,弱筋小麦扬麦13比强筋小麦烟农19的耐受性强.杀虫剂处理主要是通过降低叶片叶绿素含量、光系统Ⅱ的实际光化学效率(ΦPSⅡ)和光化学荧光淬灭系教(qP),引起单叶光合速率下降,最终导致小麦产量降低.