山奈不同溶剂提取物对DPPH自由基的清除作用

[目的]为山奈的综合利用和新型天然抗氧化剂的开发提供理论依据。[方法]山奈干燥粉碎后,用石油醚索氏抽提脱脂,以95%乙醇为溶剂,超声提取得山奈粗提物。粗提物依次用乙酸乙酯、正丁醇和重蒸水萃取,分别得到乙酸乙酯提取物（EAK）、正丁醇提取物（BK）和水提取物（WK）。用清除DPPH自由基法测试山奈不同溶剂提取物的抗氧化活性。[结果]对0.081mg/mlDPPH自由基清除率为50%时,山奈的乙酸乙酯提取物（EAK）、正丁醇提取物（BK）和水提取物（WK）的使用浓度分别为5.48、1.10、10.02mg/ml,3种提取物对自由基的清除能力（DPPH质量/提取物质量）分别为14.78、73.64、8.08。[结论]山奈正丁醇提取物对自由基的清除效果最好。     

澳洲坚果品种‘HAES951’为母本的杂交试验

以澳洲坚果品种‘HAES951’为母本,采用9个品种的花粉授粉,获得9个全同胞家系苗木。观测各组合的坐果率、种子横径和杂交F1代苗木的株高、地径及冠幅。结果表明:组合间的坐果率和种子横径均达极显著差异(P0.01);家系内株高、地径、冠幅的变异系数范围在13.67%~30.25%,平均为20.81%。9个全同胞家系间苗木的株高、地径差异不显著,冠幅达显著差异(P0.05)。     

Pollination, Fertilization and Seed Development in Inbred Lines and F1 Hybrids of Spring Faba Beans (Vicia faba L.)

When the flowers are not disturbed, the yield of F₁ hybrids of faba beans normally exceeds that in their inbred parents. The basis of this “heterotic autofertility” was investigated by examining flowers for pollination and fertilization throughout the flowering season and assessing the distribution of seeds and pods on mature plants. Six inbred lines and seven of their F₁ hybrids were grown without protection from bee visitation, and their autofertility was estimated’ by comparing their fertilization with that of cytoplasmic male-sterile line. The first direct evidence was obtained that heterotic autofertility acts by increasing; the proportion of flowers which were pollinated and fertilized. The autofertility was not perfect, especially in a closed-flower hybrid, as many ovules remained unfertilized. Several factors contributed to the number of seeds per pod in F₁ hybrids, being superior to parental means: (1) more ovules per flower, (2) greater fertilization of the basal ovules, (3) reduced abortion of the apical ovules and (4) greater overall maturation ovules.     

Breaking the crossability barriers between disomic tetraploid Solanum acaule and tetrasomic tetraploid S. tuberosum

Summary A combination of compatible second pollinations and embryo rescue was applied for systematic production of true tetraploid hybrids from crosses between disomic tetraploid Solanum acaule and tetrasomic tetraploid potato, S. tuberosum. Several genotypes of tetraploid potatoes were pollinated with S. acaule, and the compatible second pollinations were made on the following day, with a genotype of S. phureja, IvP 35 to promote fruit development. Embryo rescue was carried out in 21 families, 14 to 27 days after the first pollination. A total of eight plants were obtained from the embryo rescue and their chromosome numbers were counted in the root tips. Three of the eight plants were identified as tetraploid, and five others as diploid. Morphology, isozyme banding patterns, and pollen stainability, as well as potato spindle tuber viroid (PSTVd) resistance, indicated the hybrid nature of the three plants. This is the first report of successful tetraploid hybrid production between disomic tetraploid S. acaule (4x) and tetrasomic tetraploid potatoes. Seed set from the crosses between one of hybrids and diploid potatoes indicated workable levels of both male and female fertility for introgression of valuable genes from S. acaule into the cultivated potato gene pool. The methodology used may be applied to other disomic tetraploid tuber-bearing Solanum species and with some modifications also to distantly related solanaceous species and genera.     

百山祖冷杉异砧嫁接试验初报

百山祖冷杉天然更新困难，为解决这种冷杉的繁殖更新问题，采用以日本冷杉为砧木的异砧嫁接试验，初获成功。     

不同发育期及授粉方式对设施甜瓜中稳定同位素比值变化的影响研究

为探究不同发育期及授粉方式对设施甜瓜稳定同位素比值变化的影响,本研究基于元素分析——稳定同位素比率质谱(EA-IRMS),测定在不同发育期和授粉方式中设施甜瓜的4种稳定同位素比值(δ¹³C、δ¹⁵N、δ¹⁸O和δ²H),采用单因素方差分析法解析激素授粉和中华蜜蜂授粉对甜瓜稳定同位素比值的差异性。结果表明,在相同的种植和环境条件下,自然分馏效应导致设施甜瓜在不同发育时期的同位素差异。在甜瓜发育期间,不同授粉方式设施甜瓜的δ¹³C、δ¹⁵N和δ¹⁸O值较稳定,无显著差异(P>0.05),而在发育30 d时激素授粉与蜜蜂授粉甜瓜的δ²H值分别为-43.63‰和-53.50‰,存在显著差异(P<0.05)。本研究初步揭示了稳定同位素在甜瓜发育过程中以及不同授粉方式下的分馏情况,其中δ²H值可作为甜瓜授粉方式的一项标识性指标,对丰富设施甜瓜溯源体系具有重要意义。     

新疆野苹果传粉生物学的初步研究

对野生苹果在新疆伊犁地区的开花物候、花粉活力、柱头可授性、繁育系统和访花昆虫及访花行为进行了观察.结果表明:在整个开花过程中,从花序出现到花朵凋谢,历时较长,可达30 d以上;不同海拔,开花期相差4～14 d;一个居群的花期达30 d左右;通过对花粉活力的测定结果分析表明,花粉的活力较高,花粉平均活力达64%;用两种方法测定柱头可授性所得的结果具有一定的差距,但差异不显著;在整个花期中,昆虫的访花行为与天气密切相关.     

3种蜜蜂巢脾抗氧化活性的比较研究

[目的]通过对自由基清除效果的分析,比较3种蜜蜂巢脾的抗氧化作用。[方法]以意蜂的新、老巢脾和中蜂老巢脾为研究对象,采用DPPH.法、邻二氮菲比色法和邻苯三酚自氧化法研究不同蜜蜂巢脾对DPPH.、.OH-以及.O2-自由基的清除效果。[结果]相同浓度下的3种蜜蜂巢脾对DPPH.和.OH-的清除效果较好,而对O2-的清除效果相对较弱。蜜蜂巢脾对自由基的清除效果随质量浓度的升高而增加。3种蜜蜂巢脾中,意蜂老巢脾对自由基的清除效果好于中蜂老巢脾和意蜂新巢脾。[结论]蜜蜂巢脾具有明显的抗氧化作用,老巢脾水提液和醇提液均是良好的天然自由基清除剂。     

SOD对紫外辐射受损的苏云金芽孢杆菌作用的研究

探讨了超氧化物歧化酶 (SOD)等自由基清除剂对苏云金芽孢杆菌紫外辐射的影响。结果表明 ,SOD、绞股蓝皂甙等自由基清除剂能够明显地提高紫外辐射损伤细胞的存活率 ,并且SOD的保护作用表现为防护与恢复两种不同的作用。又通过细胞电泳与琼脂糖凝胶电泳发现紫外辐射后其细胞膜及质粒DNA均受到了明显的损伤 ;SOD对细胞膜损伤有一定的恢复作用 ,而对DNA不表现恢复效应。由此认为 :紫外线对细胞膜及DNA均有损伤 ,SOD恢复作用的主要部位在细胞膜而不是DNA分子。为进一步确定SOD的作用以及利用自由基清除剂制备高效的Bt农药提供了理论基础。     

干旱胁迫对小麦幼苗活性氧清除能力的影响

研究不同干旱胁迫方式对小麦幼苗活性氧清除能力的影响,测定小麦对羟自由基(.OH),过氧化氢(H2O2)和超氧阴离子自由基(O2-.)的清除能力变化,分为间断干旱胁迫和持续干旱胁迫两种。结果表明:正常生长的小麦具有一定的清除活性氧(.OH,H2O2,O2-.)的能力;间断干旱胁迫和持续干旱胁迫都会对小麦活性氧清除能力造成影响,总体上是使活性氧清除能力上升,根和叶对相同处理表现出不同的反应;与间断干旱比较,持续干旱对小麦活性氧清除能力的影响较大且延续时间长,持续干旱处理使小麦表现出更强的活性氧清除能力;复水后,小麦活性氧清除能力表现出不同的变化。