咸水滴灌对棉花生长和离子吸收的影响

大田试验研究了膜下滴灌方式利用咸水灌溉对棉花生长和离子吸收分配的影响.结果表明,利用3.62 dS·m-1的微咸水进行灌溉,对棉花干物质积累量影响不大.棉株体内Cl-、Ca2 和Na 含量在棉花生育期内整体呈升高趋势.随着咸水浓度的增加,K 、Cl-、Ca2 含量升高,Na 浓度变化不大.较多的盐离子通过根部向地上部运输,向茎叶中积累,蕾铃积累较少.盐离子在棉株体内的这种区域化分布,有利于维持体内离子平衡,提高棉花耐盐性.研究认为灌溉水中的Ca2 影响了盐胁迫对棉花生长和离子的吸收和分配.     

小白菜镐和钙的亚细胞分布及钙、镉互作的研究

采用水培的方法,研究0.1 mg/L和1 mg/L镉(Cd)处理时2个小白菜品种的Cd吸收和亚细胞分布及钙(Ca),Cd互作关系.结果表明:Cd主要积累在小白菜的根中,杭州油冬儿地上部Cd含量显著高于沪青1号,但根中Cd含量相反.小白菜地上部亚细胞各组分中Cd含量随着营养液中Cd浓度增加而增加,Cd主要积累在细胞质组分中,其次为细胞壁组分,积累Cd量最少的是细胞器组分,两品种间存在差异,Cd在杭州油冬儿细胞壁组分的分配比率大于沪青1号.Ca也主要分布在细胞质组分中,0.1mg/L Cd处理时,细胞质及细胞壁中的Ca,Cd为协同作用;1 mg/LCd处理时,二者为拮抗作用.     

外源氯化钙对盐胁迫下西兰花抗氧化酶系统及离子吸收的影响

摘要：以美国“格福”与日本“山水”两种耐盐性不同的西兰花为试验材料,采用基质营养液栽培,研究了外源氯化钙对盐胁迫下西兰花鲜重、干重、MDA、抗氧化酶活性及离子吸收的影响。结果表明：外源钙的添加,可显著促进西兰花的生长,减轻盐胁迫,增加地上部、地下部干重及鲜重。外源钙处理明显降低了西兰花叶片MDA含量,减轻盐胁迫对叶片膜脂过氧化程度。外源钙处理对西兰花SOD、POD、CAT活性的影响因品种耐盐性不同表现不一。外源钙处理可减少西兰花地上部、地下部Na+的积累,增加K+、Ca2+　的浓度。外源钙处理对盐敏感品种的效果要好于耐盐品种。最佳的钙浓度为10mmol/L。     

盐胁迫对薏苡种子萌发及幼苗生长的影响

以小白壳薏苡为试验材料,比较Na Cl、Na HCO3、Na2SO4、Na2CO3对其种子萌发及幼苗生长的影响。结果表明,随着Na+浓度的升高,4种盐处理薏苡种子的发芽势、发芽率、发芽指数、活力指数、根长、芽长总体呈下降趋势,抑制性Na2CO3Na HCO3Na2SO4Na Cl;薏苡幼苗生长中,丙二醛(MDA)、脯氨酸(Pro)含量及Na2SO4、Na Cl处理中过氧化物酶(POD)活性呈上升趋势,均在250mmol/L[Na+]时达到最高;过氧化氢酶(CAT)及Na2CO3、Na HCO3处理中POD活性呈先增后降趋势,Na+浓度分别为200和150mmol/L时两酶活性最高。     

海水胁迫对3种海南滨海乡土藤蔓植物种子萌发及幼苗生理影响研究

研究对比了不同浓度海水对海南乡土藤蔓植物种子萌发的影响,为海南地区海岸带地被绿化提供依据。选取海南海滩常见的3种耐盐乡土藤蔓植物:海刀豆(Canavalia maritima)、单叶蔓荆(Vitex trifolia var.simplicifolia)、马鞍藤(Ipomoea pes-caprae),分别用不同浓度的海水处理3种植物的种子,分析其发芽指数以及幼苗的主要生理指标。研究结果显示,随着海水浓度的增加,3种藤蔓植物种子的发芽率均呈下降趋势,海刀豆的发芽率整体高于其他2种植物,当海水浓度为1%时,3种植物种子的发芽势均比对照显著提高。随着海水浓度提高,3种植物幼苗的CAT、POD活性呈先上升后下降的趋势,而MDA随海水浓度提高活性逐渐上升。因此,高浓度海水对3种耐盐藤蔓植物种子萌发有一定程度的抑制,低浓度的海水处理对提高植物种子的耐盐性有一定积极意义。     

耐盐杂草稻幼苗对NaCl胁迫响应及其生理基础

采用人工气候箱水培试验,研究了不同浓度NaCl处理对杂草稻幼苗生长、根系特性和渗透调节物质的影响.结果表明,随NaCl处理浓度的增加,3个试验材料苗高、地上部鲜质量、地上部干质量、地下部鲜质量和地下部干质量均降低,且降幅均为越光﹥长白9号﹥WR03-12.低NaCl胁迫下,WR03-12主根长有增加趋势.随NaCl浓度增加,3个材料根系总根长、根系体积、总表面积、吸收面积和活性吸收面积均呈下降趋势,下降幅度越光最大,长白9号居中,WR03-12最小.随NaCl浓度增加,3个材料游离氨基酸、可溶性糖含量均显著增加,增幅均为WR03-12﹥长白9号﹥越光,脯氨酸含量也随胁迫浓度增加而上升,增幅为越光﹥长白9号﹥WR03-12.     

杂草稻幼苗对Na2CO3+NaHCO3胁迫响应及其生理基础

采用人工气候箱水培试验,研究了不同浓度Na2CO3+NaHCO3处理对杂草稻幼苗生长、根系特性和渗透调节物质的影响.结果表明,随Na2CO3+NaHCO3胁迫浓度的增加,3个试验材料苗高、生物量积累、主根长、根系总长度、根系表面积和根系体积均降低,根系总吸收面积和活性吸收面积减小,且降幅均为越光＞长白9号＞ WR03-...     

北美海蓬子盐胁迫条件下抑制差减文库构建与分析

北美海蓬子(Salicornia Bigelovii Torr.)是一种耐盐性极强的真盐生植物,在200 mmol/L的Na 浓度下生长,其高度和含汁量是5 mmol/L Na 浓度下生长的2倍和2.5倍.为了研究北美海蓬子耐盐的机理和分离耐盐新基因,我们构建了在盐胁迫条件下北美海蓬子基因表达差异的SSH文库.以北美海蓬子种子播种于0 mmol/L NaC1 MS液体培养基上幼苗(0号材料)的总RNA为Driver,200 mmol/L NaCl诱导24 h幼苗(2号材料)的总RNA为Tester,运用SMART PCR cDNA合成技术分别合成全长cDNA.将两种cDNA群体进行抑制差减杂交,用T/A法分别构建了盐胁迫相关基因的正向差减文库(205个克隆子)和反向差减文库(235个克隆子).通过PCR和反式Northern Dot.Blot消除假阳性和重复克隆子,得到在盐胁迫下特异表达的阳性克隆85个.对测序结果正常的81个克隆进行BLASTn分析,其中有70个cDNA序列与已经报道的其它物种的核酸序列具有较高的同源性;另外11个cDNA序列未找到有较高相似性的已知序列.81个cDNA序列中没有与北美海蓬子中已报道的核酸序列有较高的相似性,因此,所有81个克隆序列都是北美海蓬子中的新基因.     

小白菜镉和钙的亚细胞分布及钙、镉互作的研究

采用水培的方法,研究0.1 mg/L和1 mg/L镉(Cd)处理时2个小白菜品种的Cd吸收和亚细胞分布及钙(Ca)、Cd互作关系。结果表明:Cd主要积累在小白菜的根中,杭州油冬儿地上部Cd含量显著高于沪青1号,但根中Cd含量相反。小白菜地上部亚细胞各组分中Cd含量随着营养液中Cd浓度增加而增加,Cd主要积累在细胞质组分中,其次为细胞壁组分,积累Cd量最少的是细胞器组分,两品种间存在差异,Cd在杭州油冬儿细胞壁组分的分配比率大于沪青1号。Ca也主要分布在细胞质组分中,0.1 mg/L Cd处理时,细胞质及细胞壁中的Ca、Cd为协同作用;1 mg/LCd处理时,二者为拮抗作用。     

NaCl和Na2CO3胁迫对菊芋幼苗生物量的影响

采用无土盆栽方式,以菊芋为材料研究不同浓度的NaCl,Na2CO3胁迫下菊芋幼苗总鲜重、根、茎、叶鲜重、干重、叶绿素含量等生物量变化。结果表明：低浓度25mmol．L-1的NaCl促进幼苗的生长,与对照相比生物量略增;当NaCl浓度为100mmol.L-1～200mmol.L-1时幼苗的生长受到抑制,生物量、叶绿素含量呈降低趋势,处理之间差异不显著;当NaCl浓度＞200mmol.L-1 生物量突增。低浓度的Na2CO3促进幼苗的生长,当Na2CO3浓度＞20mmol.L-1幼苗的生长受到抑制,随浓度的递增生物量呈下降趋势,叶绿素含量也呈下降趋势。菊芋幼苗受碱胁迫比受盐胁迫强烈,说明菊芋幼苗具有很强的耐盐性。     

Intra‐ and inter‐specific crosses of Solanum materials after mitotic polyploidization in vitro

Mitotic polyploidization in vitro was used in selected wild Solanum species and Solanum tuberosum dihaploids. The efficiency of polyploidization by colchicine was compared with that of oryzalin. Oryzalin was more effective than colchicine (P = 0.1). The rate of non‐affected to mixoploid to tetraploid regenerants was 22 : 2.5 : 1 (colchicine) and 14 : 2 : 1 (oryzalin). Optimal concentrations and durations were 3.5 mm /24 h for colchicine and 25 or 30 μm for 24 or 48 h for oryzalin (variations in concentration and duration are necessary owing to possible diversity of responses in selected genotypes). Tetraploids were obtained from S. berthaultii, S. bulbocastanum, S. pinnatisectum, S. verrucosum and eleven S. tuberosum dihaploids. The yield of tetraploids derived from tbr dihaploids was lower than that from the wild species (P = 0.01). Tetraploid regenerants were tested in intra‐ and inter‐specific crosses. Three of 43 intra‐specific combinations (298 pollinated flowers) were successful and yielded 440 seeds. Inter‐specific crosses (138 combinations, 1672 pollinated flowers) yielded 48 seedless berries.     

Potato germplasm development for warm climates: genetic enhancement of tolerance to heat stress

Complex potato hybrids were derived through unilateral sexual polyploidization between Solanum tuberosum cv. Atlantic and 11 diploid hybrids that produced 2n pollen through co-orientation of second division spindles. The hybrids represented the following genomic compositions: TAPB, TAPC, and TAPM where T = S. tuberosum, A = S. andigena, P = S. phureja, B = S. berthaultii, C = S. chacoense, and M = S. microdontum. The B, C, and M components of the hybrids had been selected from heat tolerant accessions. The heat tolerance and agronomic performance of the hybrids were assessed under both controlled environments and field tests. The hybrids exhibited good tuberization potential (tuber number, tuber weight and percent plants producing tubers) under heat stress conditions in controlled environments. Under severe heat stress conditions in the field in Israel, many of the hybrids tuberized when Atlantic failed to produce any tubers at all. Under more moderate heat stress in Virginia, the complex hybrids exhibited total tuber yield not significantly different from Atlantic, although the tuber set per plant was greater. However, the complex hybrids were more tolerant to heat necrosis and hollow heart than Atlantic. Total glycoalkaloids in field-grown tubers did not exceed the acceptable limit for 13 of 26 selections examined. This revised version was published online in July 2006 with corrections to the Cover Date.     

储粮象甲对不同食料的选择性

为明确玉米象和绿豆象对食料的嗜好性,利用昆虫趋向性和产卵性进行了试验研究。结果表明：玉米象对糯玉米、高粱、小麦的正趋性和危害性明显优于对薏米和普通玉米;且玉米象喜欢选择淀粉含量较高的食料。绿豆象在黑豆、红小豆和绿豆中的产卵量较高,依次为78.75粒、77.75粒、75.75粒;而在大白芸豆上的产卵量为0粒。因此,建议在储粮过程中将淀粉含量较高的储粮分开贮存,以减轻玉米象对储粮的危害;在储藏绿豆时,可将大白芸豆覆盖在其他豆种上,起到隔离防止绿豆象危害的效果。     

利用单向有性多倍化改良马铃薯的蛋白质含量

马铃薯(Solanum tuberosum L.)蛋白质必需氨基酸平衡,通过育种手段提高其蛋白质含量将有助于改善人们的健康水平.本试验试图采用4x-2x组合方式进行有性多倍化,向普通马铃薯转移存在于二倍体栽培种Solanum Phureja和S.phureja-S.stenotomum(PHU-STN)杂种中的高蛋白基因.4x-2x四倍体杂种无性一代种植在哈尔滨和加格达奇,以早熟鲜食马铃薯品种克新4号及中晚熟高淀粉马铃薯品种克新12号为对照,评价其蛋白质含量.在14个组合中,04H19、04H21、04H23和04H17蛋白质含量(干基)均高于克新4号和克新12号,但它们只和克新12差异显著;当以鲜基表示蛋白质含量时组合间差异不显著.无论是以鲜基还是以干基为基础表示蛋白质含量均能从4x-2x四倍体后代中鉴定出高蛋白质的无性系.这些材料为进一步选择或当作亲本改良马铃薯蛋白质含量提供了物质基础.     

利用虫体蛋白特异性区分三种象虫

本文报道了利用聚丙烯酰胺凝胶电泳（PAGE）和凝胶渗透液相色谱法（GPC）分别对3种象虫虫体蛋白进行分离分析。初步分析结果表明：凝胶电泳法具有较高的分辨能力，电泳图谱能明显地区分3种象虫；凝胶渗透液相色谱法分析结果无差异，但对3种象虫虫体蛋白的胰蛋白酶水解液的分离结果有明显的区别。     

泰山椴扦插繁殖技术研究

为了给泰山椴的保护和快速繁育提供理论依据,笔者研究了插条不同部位（上、中、下）、不同插穗类型以及不同激素种类(IBA、NAA、TBT)和浓度(500、1500、3000、5000 mg/L)对泰山椴扦插生根的影响。结果表明：插条中段的插穗生根效果最好,其生根率为45.6%,上段为39.7%,下段为35.2%;不同插穗类型对泰山椴扦插生根影响显著,其中8月上旬时的半木质化嫩枝生根率为52.3%,是9月中旬木质化硬枝的1.1倍;不同激素和浓度处理对泰山椴扦插生根影响显著,其中以IBA 3000 mg/L生根效果最好,其生根率为68.5%,平均根数为18.6条,平均根长为12.35 cm,分别是对照的2.6倍、1.4倍、1.2倍。泰山椴扦插宜选用半木质化枝条的中段为插穗,经IBA 3000 mg/L溶液处理效果最佳。     

中国对美国蔬菜出口的现状、问题和对策

蔬菜是中国农产品中的优势出口品种,目前中国已经是世界上最大的蔬菜出口国家。近年来中国对美国的蔬菜出口增长迅速,但发展的潜力仍然巨大,进一步扩大对美国的蔬菜出口,对提高农民收入,发展农村经济具有十分重要的现实意义。分析了中国对美国出口蔬菜的现状,美国对蔬菜的市场需求,以及中国蔬菜的比较优势,探讨了制约中国蔬菜出口的主要问题,并提出了相应的对策建议。     

小米空木耐阴性研究

为了研究小米空木的耐阴性问题,以小米空木为试验材料,采用人工遮阴的方法对2~3年生小米空木进行研究。通过人工遮阴,分别使其处于全光照的2.5%、5%、10%、20%、40%以及70%条件下生长,并设全光照对照,对其生长增量、叶绿素含量、脯氨酸含量以及POD活性等进行测量及测定分析。结果表明：20%~40%光照为小米空木的适宜光环境;在全光照条件下生长较好,但叶片易出现枯黄、褐斑及翻卷现象;小米空木最低可在5%光照条件下生长,叶片小而均匀。     

Comparison of haploid Tuberosum-Solanum chacoense versus Solanum phureja-haploid Tuberosum hybrids as staminate parents of 4x–2x progenies evaluated under distinct crop management systems

The relative value of haploid Tuberosum-Solanum chacoense (TCH) vs. Solanum phureja-haploid Tuberosum (PTH) hybrids as male parents in 4x–2x crosses was estimated under two distinct crop management systems. The first experiment (E#1) was carried out with supplementary irrigation (three times a week) at Hancock-Wisconsin (WI) with 27 families derived from a sub-set of crosses involving 11 tetraploid (4x) cultivars and 10 diploid (2x) clones (3 TCH; 6 PTH; and one TCH-PTH hybrid clone). A second experiment (E#2) was conducted at Rhinelander-WI with the same group of families but it was only rainfed with no supplementary irrigation being provided during the entire course of the assay. For comparison, a complete set of 4x and 2x clones (used as parents) was also planted in each location. Three traits were evaluated in both locations: total tuber yield (TTY), haulm maturity (HM), and plant vigor (PV). Altogether, 18 out of 27 and 10 out of 27 families outyielded the corresponding 4x parents at E#1 and E#2, respectively. Significant differences among all 4x–2x families and among families of the TCH group were observed for TTY at both locations. No difference was found for TTY among families of PTH and [TCH–PTH] groups at each location. A total of 75% and 50% of the TCH families outyielded their 4x parents at E#1 and E#2, respectively. The percentage of families from the PTH group that outyielded their 4x parents at E#1 and E#2 was 83.3% and 25%, respectively. The TCH group had on average lower HM scores than PTH (at both locations) indicating some segregation for earliness. However, the HM values of the 4x–2x families were, in general, higher than those observed for the 4x parents. For PV, the PTH group mean was significantly higher than TCH group only in E#1. The PV values of the 4x–2x families were higher than the 4x-parent group at both locations. Our results indicated that TCH hybrids might be as good parents as PTH to increase the TTY of 4x–2x progenies. In addition, the TCH families displayed a slight higher level of performance under more stressful growing conditions than PTH hybrids as indicated by the assay at Rhinelander. Therefore, selection of genetic materials with potential broad range of adaptation seems to be feasible with both hybrids via the 4x–2x breeding scheme. This revised version was published online in July 2006 with corrections to the Cover Date.     

中国对美蔬菜出口的现状、问题和对策

蔬菜是中国农产品中的优势出口品种,目前中国已经是世界上最大的蔬菜出口国家。近年来中国对美国的蔬菜出口增长迅速,但发展的潜力仍然巨大,进一步扩大对美国的蔬菜出口,对提高农民收入,发展农村经济具有十分重要的现实意义。分析了中国对美国出口蔬菜的现状,美国对蔬菜的市场需求,以及中国蔬菜的比较优势,探讨了制约中国蔬菜出口的主要问题,并提出了相应的对策建议。