Abstract:用压片法对八倍体小偃麦与硬粒小麦及其杂种F_1小孢子发生和花粉发育进行了详细的细胞学观察。结果表明,两亲本八倍体小偃麦和硬粒小麦的小孢子发生和花粉发育是基本正常的,二者结实率也基本正常。[八倍体小偃麦×硬粒小麦]F_1小孢子发生过程非常紊乱,花粉母细胞减数分裂中期Ⅰ出现较高频率的单价体和多价体,其相对紊乱系数高达0.67;减数分裂晚后期,每个细胞落后染色体平均3.56条;四分体期,每个四分体微核数平均2.82个。在杂种F_1花粉发育的每个时期都可产生不同频率的败育花粉。在三细胞成熟花粉期,杂种F_1可育花粉百分率为67.36%,基本能够满足传粉受精的需要,但其结实率仅为2.79%,远远低于两亲本结实率。因此杂种F_1花粉的败育不是导致其结实率低的主导因素。

Abstract:The morphological characteristes of spores in Onocleaceae were studied by scanning electron microscops. Based on the results of observations, some classification problems were discussed. 1. Onoclea sensibilis var. interrupla Maxim. is different from O.sen

Abstract:1987—1989年在人工模拟降雨室对123个小麦品种进行了成熟期穗发芽抗性鉴定。重点研究了13个品种的穗发芽率、籽粒发芽率、籽粒含水量,籽粒吸水速率和α-淀粉酶活性的动态变化。并通过6个抗性不同品种的双列杂交,初步探讨了穗发芽抗性的遗传特点。结果表明:红粒品种普遍抗穗发芽,但白粒品种中也存在不少抗源;开花后35—40天是鉴定穗发芽抗性的适宜时期;这个对期的仔粒吸水速率阳α-淀汾酶活性是抗性鉴定的可靠指标;穗发芽抗性是遗传性状,存在母、子体抗性因子互作效应。

Abstract:The zygote of Brasiica campestris ssp. pekinensis elongates considerably before its first unequal transverse division forming a 2-celled proembryo. Another two divisions give rise to the 3- and 4-celled proembryos, which is followed by still another two d

Abstract:Wound-induced respiration and ethylene production were significantly increased in aged discs of preclimacteric apple fruit. Ag~+ and AVG obviously inhibited the induced respiration, indicating that wound-induced ethylene take a important role in the devel

Abstract:With methods of CO_2 exchange analyse, acid content and phosphoenolpyruvate carboxylase activity determination, the photosynthetic type was studied in Sedum spectabile, a widely distributed plant in China. The mature leaves in well watered plants were of

Abstract:“秦冠”苹果种子的总呼吸强度和EMP途径的呼吸强度在2℃条件下层积之后逐渐增加,解除休眠临界期大体在层积后第30天发生,此后增长速度较快。HMP途径和TCAC在临界期之前变化极慢,而后急剧增加。种子萌发后子叶和胚轴的总呼吸强度、EMP和TCAC初期呈急剧上升趋势,大约当胚轴长度达2cm时迅速下降,HMP在萌发过程中始终呈上升趋势。细胞透性层积之后逐渐降低,解除休眠至萌发阶段呈上升趋势。用不同浓度呼吸抑制剂处理解除休眠种子的试验结果表明,除1mM碘乙酸能明显刺激萌发和生长外,NaCN、SHAM和丙酮酸都表现为抑制作用。

Abstract:The anomalous secondary structure and growth in the stem of xerophyte, Ceratoides latens, was studied. A developed stem consists of phellem which is well developed, Anomalous strands was arranged at random and embedded by lignified as well as sclerified c

Abstract:The abaxial leaf surfaces of 14 species of the genus Epimedium L. were studied under LM and SEM. It was found that the cuticular ornamentaions and trichomes possess the diagnostic value of species. Distinguished characteristics of each of 14 species is de

Abstract:Loess plateau is located between asiatic inland and eastern Asia. It is generally known as a famous area with the deepest loess deposit in the world. For this reason, the flora of Leguminosae in this area are provided with transitional charactors, the flo

Abstract:This paper has summarized absorption and accumulation of radionuclides in lichens and effects of environmental factors. Application of lichen in environment radioactivity monitoring and problem existed is talked over, and a dynamic model for radionuclide