辐照花粉对玉米F_1M_1结实及后代植株的影响

用6 0 Coγ射线辐照玉米杂交种 (F1)的花粉 ,然后采取自交方法授粉 ,以探讨辐照花粉对F1M1结实及后代植株的影响     

Life cycle of pollen grains in mormoder humus forms of young acid forest soils: a micromorphological approach

Horizons of humus profiles contain pollen and spores. The palynological information of pollen spectra of terrestrial humus forms must be validated by micropedological knowledge of the processes of infiltration, incorporation, conservation, transport and decay of pollen grains in the soil system. This study presents the results of combined palynological and micromorphological analyses of two mormoder humus forms, sampled in the Forestry Gieten, The Netherlands. The aim of this study was to establish the distribution pattern and life cycle of pollen grains in mormoders. The first step of this cycle of pollen grains in the humus profile is eolian deposition on the soil surface. The second step is incorporation of the grains in organic aggregates in the upper part of the F horizon. In ‘acid’ mormoders, grains are embedded by ageing small excrements of micro-arthropods and incorporated in the resulting organic aggregates. In ‘mild’ mormoders, the same process is observable, but additional pollen grains are also directly incorporated (and slightly transported) in medium excrements of small earthworm. The third step in the cycle is release by microbial attack of the aggregates in the lower part of the F horizon and the H and Ah horizons. The fourth step is re-incorporation of the released grains in organic aggregates of ageing small sized excrements of micro-arthropods, which consume decaying root tissue. Not re-incorporated grains will finally mineralise by microbial consumption. Mineralising of released pollen grains is the main process in the mineral AE horizon. Based on knowledge of the distribution pattern and life cycle of pollen grains in mormoders, pollen diagrams can be used for the reconstruction of the forest development.     

四倍体与二倍体棉花远缘杂交后代同工酶电泳分析

４００Ｇｙ＾６０Ｃｏγ射线蝠照中棉花粉，９０２０７受粉后获得二倍体棉与四倍体棉间的远缘杂交后代，对其Ｆ３、Ｆ４（２ｎ＝５２）进行了同工酶电泳分析，结果发现，Ｆ３独杆类型后代的过氧化物酶同工酶谱中有父本中棉的特异带。Ｆ４个别纤弱，小铃株系的过氧化物酶和细胞色素氧化酶同工酶中也有父本影响的趋势。以上均证明，少量二倍体遗传物质进入四倍体细胞中，远缘杂交后代，独杆类型较多地具有阿须莫尼的特点，而分枝类型后     

辐照花粉促进普通小麦与窄颖赖草属间杂交的研究

通过研究小麦基因型、γ射线辐照剂量、授粉时期等对普通小麦与窄颖赖草（ Ｌｅｙｍ ｕｓ ａｎｇｕｓｔｕｓ） 杂交结实率的影响和不同幼胚抢救方法,首次较为完善地建立了运用核辐射促进普通小麦与窄颖赖草属间杂交的配套方法程序,即选用适宜小麦基因型Ｊ １１ 作母本,用适宜剂量（５ ～９ Ｇｙ） 的γ射线辐照窄颖赖草花粉,在适宜授粉时期（ 去雄后１ｄ 、散粉前２ ～３ｄ） 授粉;采用胚 愈伤组织二步成苗法进行幼胚抢救。     

辐照小麦雄配子提高远缘杂种结实率的研究

用六倍体小黑麦黑杂２６６作母本，春小麦龙辐麦３号、龙辐麦５号为父本进行远缘杂交，杂交前用￣（６０）Ｃｏγ射线８００～２４００ｒａｄ活体慢照射雄配子。通过对杂种１代（Ｆ１Ｍ１）花粉母细胞的观察，减数分裂中期二价体平均为１３．６５，最高为１４．５５，与理论值接近，未经辐照的为１２．８０，低于理论值，辐照改善了染色体配对。辐照的Ｆ１Ｍ１代平均结实率为５５．５２％，未经辐照的为６．４９％。辐照处理明显提高了杂种１代的结实率。辐照雄配子的适宜剂量为１６００ｒａｄ和２４００ｒａｄ，不同品种间辐射敏感性有很大差别。     

空间诱变甜椒后代的花粉粒超微结构观察

本文用空间诱变后经连续4代自交授粉获得的变异体(SP06-31)和其对照L06-30为材料,评估材料的花粉生活力和扫描电镜下的花粉粒超微结构。结果发现:与对照相比,部分花粉粒表面附有不确定颗粒物,同时一部分花粉粒形状发生变异。研究认为空间环境条件可以导致甜椒后代植株花粉粒的超微结构发生改变。     

The use of micromorphology in soil pollen analysis: The interpretation of the pollen content of slope deposits in Galicia, Spain

Humic horizons of soil profiles often contain pollen and spores. Comparison of the sequence of pollen associations of soil profiles with pollen zones of reference diagrams offers palyno-ecological information, relevant for reconstruction of landscape ecological development. In palynological studies of semiterrestrial and aquatic deposits, pollen is considered to be part of the sediment and anaerobic conditions in water-saturated deposits promote its conservation. This is not true for pollen in soils. Aerobic conditions in drained soils result in bio-oxidation of unprotected pollen grains. Interpretation of soil pollen associations requires knowledge of the processes of infiltration and conservation of pollen grains in the soil material. Micromorphology is an important technique to investigate these processes. This is demonstrated in a case study of polycyclic slope deposits in Galicia (Spain). The buried cambisols, in pleistocene solifluction deposits, contain post-sedimentary infiltrated pollen. The pollen associations reflect successive phases in soil ecological development. The holocene colluvial deposits contain syn-sedimentary incorporated pollen. The pollen associations reflect environmental conditions during the deposition of colluvial layers.     

Analysis of micronutrients in olive pollen

The micronutrient content [iron (Fe), manganese (Mn), copper (Cu), zinc (Zn), boron (B)] of olive (Olea europaea L.) pollen grains from different sites is studied by means of spectrophotometry and atomic absorption techniques. We compared pollen samples collected from organic olive crops (B1, B2, and B3), cultivated without the use of mineral‐based fertilizers, phytosanitary products or herbicides with samples obtained from crops which had undergone extensive chemical treatment (T1, T2, T3, and T4). The micronutrients detected in the pollen grains analyzed show that large quantities of such chemical products are absorbed by the plant. The importance of Fe should be stressed, since in one of the chemically‐treated samples (T3) levels of 1,484 μg/g dry weight were found to have been incorporated into the structure, while in the control samples the equivalent concentrations ranged between 96 and 450 μg/g dry weight. Similarly, Cu was found to have been easily assimilated by populations which had received extensive Cu‐based foliar treatments.     

Effects of cryopreservation on germinability of olive (<Emphasis Type="Italic">Olea europaea</Emphasis> L.) pollen

Long term storage of viable pollen is important for bank germplasm constitution to preserve resources that can be used in breeding programs, biotechnologies and genetic engineering. Pollen from 12 olive (Olea europaea L.) cultivars was stored for 1 year in liquid nitrogen at −196°C. The morphology of pollen grains and germination rates on fresh and long term stored pollen were observed. Results on in vitro pollen germinability, both before and after cryopreservation, showed highly significant responses among the 12 cultivars. The relationship between germinability and pollen grain size did not reveal any significant relationships in both treatments. Our findings will contribute to the improvement of olive pollen preservation and lead to find a more efficient method for its long term storage, while retaining its germinability.     

小麦单倍体辐射诱变育种技术研究

采用不同剂量的60 Co γ射线诱变处理杂交当代干种子,以 MW14 和改良 MS 为基本培养基;从MF1 或MF2 代中选择优良单株为供体进行花药培养。针对辐射诱变剂量、低温预处理供体幼穗、变温诱导培养和低温预处理愈伤组织与花培出愈率、绿苗分化率的关系以及越夏控苗和花粉植株移栽等问题进行了研究,以提高获得遗传稳定的可育性加倍单体—纯合二倍体花粉植株的频率,通过大田系谱法可快速选育出新的小麦突变体品种( 系) 及育种材料。这种小麦单倍体辐射诱变育种途径不仅保留了辐射诱变育种固有的特点,同时可将育种周期缩短3 ～4 个世代,提高了小麦辐射诱变育种的效率。