S3307浸种对番茄幼苗抗旱性的影响

应用S3307对番茄进行浸种处理,研究其对番茄幼苗抗旱性的影响,结果表明:S3307浸种处理能够提高番茄幼苗的SOD和POD活性,提高脯氨酸、Vc含量,降低MDA含量和外渗电导率水平,进而提高了番茄幼苗的抗旱性。5mg·L-1S3307浸种的效果明显。     

几种化学调节剂对板栗杂交实生苗提早开花和生长的影响

以2 a生板栗实生苗为试材,研究了叶面喷施KT、6-BA、CCC、PP333和S3307在提早开花结果和树体生长上的应用效果.结果表明,不同药剂种类、浓度及药剂组合对板栗实生苗干粗增长率、树高增长率、新梢长度和花量及花性别分化的影响差异明显,组合药剂处理促进开花效果较好,树体对组合药剂的调节反应明显强烈于单种药剂.6-BA50mg/L PP333 1 000 mg/L和KT1 mg/L PP333 1 000mg/L喷施1次处理效果较佳,不仅较对照显著提高花芽分化量和雌花簇数,还能促进40%的实生苗至少提早1 a开花结果.     

气候因子对狭叶四照花幼苗年生长节律的影响

应用灰色系统理论中的关联分析方法,对1年生狭叶四照花苗高、地径生长量与气候因子间的关系进行了定量分析,结果表明影响其苗高、地径净生长量的主导因子分别是旬平均气温和旬降水量。     

人工模拟水分胁迫条件下小麦幼苗抗旱性鉴评指标的分析

为了明确小麦幼苗抗旱性鉴定评价的最佳时期和有效指标,以小麦加倍单倍体(Doubled haploid,DH)群体的150个株系为材料,采用模拟干旱胁迫法,研究了水分胁迫及复水条件下,幼苗叶片相对含水量、叶片相对电导率、根冠比、根干重和最大根长等五个抗旱相关性状的动态变化和遗传力,分析了各性状及其与平均隶属函数值之间的关系.结果表明,在水分胁迫72 h(WS72)和复水24 h(RW24)时,基因型之间的性状变异范围较大,是进行幼苗抗旱性鉴定评价的较好时期;平均隶属函数值不仅受各性状的直接影响,还受到性状之间交互作用的影响.在选择适当的与抗旱性关系密切性状的基础上,估算平均隶属函数,作为评价抗旱性的综合指标,可能是进行作物抗旱性综合评价的有效途径.     

不同耕作措施对土壤水热状况及玉米幼苗生长发育的影响

针对辽宁省中西部地区春旱频繁及土壤风蚀严重的特点,采用1∶2轮耕、1∶1轮耕、铁茬垄侧播种、铁茬茬间播种、铁茬茬间播种覆盖、保墒蓄水耕作及灭茬后原垄播种(对照)等耕作措施,研究其对玉米苗期土壤水热状况及玉米幼苗生长发育的影响。结果表明:各种耕作措施的土壤含水量均高于对照,其中铁茬茬间播种覆盖更加明显;不同耕作措施下耕层土壤温度从整体上表现为留茬覆盖<留茬<灭茬;1∶2轮耕的幼苗干物重最大;铁茬茬间播种处理的幼苗性状明显优于其它耕作措施。     

种薯大小对脱毒甘薯出苗数量和质量的影响

[目的]确定脱毒甘薯[Ipomoea batatas（L）Lam．]育苗时适宜的种薯大小。[方法]设1个对照和13个处理,其中对照为混装（50-500g种薯占重量的85％,500-700g为15％）,13个处理的种薯重量分别为50-100、101-150、151-200、201-250、251-300、301-350、351-400,401-450、451-500、501-550、551-600、601-650、651-700g。[结果]种薯大小对出苗数量和质量有一定影响。50-200g薯块出苗最多,较对照差异显著,50-100g薯块薯苗茎细且鲜重小,均与其他处理差异显著。200-300g薯块采苗数虽和对照差异不显著,但是与100-200g薯块采苗数量和质量相差不大。[结论]综合分析认为,对于脱毒忻薯2号,在生产上100-300g薯块作为种薯育苗比较适宜。     

Structure of the advanced regeneration community in tropical rain forest fragments of Los Tuxtlas, Mexico

We characterized the tree seedling community within seven forest fragments of different size (3-640 ha) at Los Tuxtlas, Mexico. We considered individual density, species richness, diversity, composition and functional group (shade tolerant, non-pioneer-light demander and pioneer species). We recorded 8038 individuals, belonging to 128 species and 40 morphospecies. Overall, shade-tolerant species had the highest density and diversity followed by non-pioneer-light demanders and pioneer species. Mean individual density per plot was not related to fragment size, but mean species richness per plot, total observed species richness and diversity were inversely related to fragment size, with the smallest fragments having the highest values. Species composition comparisons highlighted low similarity among fragments. Furthermore, larger fragments shared more species with the smallest fragments than between each other. Our results show that the largest fragments do not always hold the highest species richness; that small fragments comprise of high seedling species diversity, and represent a high regeneration potential for tree native species in the study landscape.     

苗期水分胁迫对玉米根系生长杂种优势的影响

以玉米杂交种高油115及其亲本(母本220、父本1145) 为材料, 研究了玉米苗期根系生长的杂种优势及水分胁迫的影响。试验设水分充足、轻度干旱和严重干旱3个处理, 田间持水量分别为75%、55%和35%。结果表明, 在水分充足条件下, 根长(RL)、根表面积(SA)和根干重(RDW)均表现出不同程度的中亲优势和超亲优势, 轻度干旱显著降低了各指标的杂种优势, 而严重干旱则完全抑制了根系生长的杂种优势。根系各性状中, RL的杂种优势最强。在水分充足条件下, 与中等根(根直径0.25~0.45 mm)和粗根(根直径>0.45 mm)相比, 细根(根直径0.05~0.20 mm)的RL、SA及其占总根系比例的杂种优势最高。轻度干旱胁迫虽然降低了根系的杂种优势, 但RL、SA仍表现出显著的超亲优势和中亲优势(粗根的超亲优势除外)。此外, 只有细根RL和SA占总根系的比例在轻度干旱胁迫下具有显著的中亲优势, 说明杂交种可以通过生成较亲本更高比例的细根来抵抗轻度干旱胁迫。     

Are marginal beech (<Emphasis Type="Italic">Fagus sylvatica</Emphasis> L.) provenances a source for drought tolerant ecotypes?

Due to the expected increases of number and intensity of summer droughts in Central Europe the identification of drought tolerant ecotypes becomes more important in future forestry. A common garden experiment with seedlings of Fagus sylvatica provenances from the center (Germany) and eastern margin (Poland) of the species’ distribution range was conducted. Responses of morphological, physiological, chemical and growth parameters to three drought treatments were analyzed. Relative growth rates of the marginal provenance were lower as compared to the central provenance. The marginal seedlings showed a tendency to higher total biomasses because of higher seed masses. In both provenances drought decreased biomass production and root/shoot ratio which was lower in the central provenance. A lower specific root area of the marginal provenance indicated a better adaptation to low xylem water potentials. Under moderate drought, lower leaf δ¹³C signatures may indicate lower stomatal limitation (or a reduced rate of CO₂ assimilation) in the marginal provenance. We conclude that marginal beech provenances may exhibit a better drought adaptation.     

不同溶液及水质中四季海棠(Begonia semperflorenshybr)幼苗生长状况研究

［目的］研究四季海棠（Begoniasemperflorenshybr）幼苗在汞、阿特拉津溶液及不同水质中的生长状况。［方法］利用水培试验研究了重金属汞和有机污染物阿特拉津以及自来水、蒸馏水、湖水（吉林农业大学湖中的水）对四季海棠幼苗生长的影响。［结果］汞溶液对四季海棠生长的抑制作用随浓度的增加逐渐增强,随着浓度和时间的增加毒害越重;阿特拉津对四季海棠生长的抑制作用随着浓度的增加逐渐减弱,但生存的海棠生长性状已不健康,不具有观赏价值。四季海棠在自来水、蒸馏水、湖水中的生长状况以湖水较好,说明四季海棠可以适应水生环境的驯化。［结论］为汞在园林中更广泛的应用提供了科学依据。