CO_2浓度倍增对大豆生长及光合作用的影响

以‘齐黄27’大豆为材料,研究人工气候室模拟大气CO2浓度倍增(700μmol.mol-1)的环境条件下大豆植株在生长、色素含量及光合作用相关指标的变化。结果表明:CO2倍增显著增加株高、干鲜重和根瘤数,显著降低根冠比;CO2浓度倍增处理增加了叶绿素、花青素和类胡萝卜素含量,使光合速率、Rubsico的活性、气孔导度和PSⅡ的功能都有所增加。CO2浓度倍增处理对大豆植株的生长具有促进作用,主要是由于高浓度CO2增加了根瘤的数量,增加了叶片叶绿素和类胡萝卜素含量,提高了Rubsico活性,增强了PSⅡ功能并且提高了气孔导度,最终使光合速率增加所致。     

雌核发育翘嘴鲌胚胎发育和形态特征的研究

在成功获得翘嘴鲌减数分裂型雌核发育鱼的基础上,观察比较了雌核发育胚胎与单倍体胚胎和普通胚胎的发育特征及时序差异,探讨了冷休克处理对胚胎发育的影响及完善雌核发育胚胎孵化管理的措施,并对雌核发育翘嘴鲌成鱼进行了形态学特征分析。结果表明:(1)与普通胚胎相比,雌核发育胚胎受精率较低且仔鱼畸形率较高,单倍体孵化率极低。(2)雌核发育组胚胎出现不规则细胞分裂、卵膜破裂、卵黄囊凝集及单倍体综合征等现象,其中原肠期和出膜前期为胚胎死亡高峰期。(3)雌核发育二倍体与普通胚胎的发育特征相似,卵裂至原肠期阶段发育特别缓慢,原肠期以后,各期发育所用时间与普通胚胎基本相同;单倍体胚胎卵裂开始至囊胚阶段,发育速度与普通胚胎无明显差异,在原肠期阶段发育滞后,其他时期一直处于缓慢状态,仔鱼具有明显的单倍体综合症。(4)雌核发育系体型较普通翘嘴鲌已经发生了一定的变化。     

小麦DH群体数量性状的遗传分析

为了研究小麦数量性状的遗传规律,利用郑州8761×川育35050杂交组合的F1花药培养获得的DH群体对小麦株高、穗下节长、穗长等性状进行了遗传分析.结果表明,株高、穗下节长、穗长、单株穗数、结实小穗数、不育小穗数、总小穗数、穗粒数这8个性状的遗传力分别为92%、83%、79%、30%、48%、48%、53%和47%;控制各性状的最少基因对数分别约为5、6、10、12、11、11、11和9对.各性状的偏度系数和峰度系数的估算结果表明,控制株高、穗下节长、穗长、结实小穗数、总小穗数和穗粒数的基因间无互作,控制单株穗数和不育小穗数的基因间存在互补作用.     

玉米单倍体诱导系对不同类群F_1的诱导率评价

为了规模化应用玉米单倍体育种技术,研究了玉米单倍体诱导系高诱1号和EMK-1对不同基因型类群F1的单倍体诱导效果。结果表明:诱导率和母本基因型存在显著差异,与不同来源父本的差异相关性接近显著水平。EMK-1诱导率和植株性状明显优于高诱1号,可以重点利用;单倍体自然加倍率与母本基因型差异接近显著水平,与父本诱导系基因型没有差异。     

不同播期对玉米单倍体自然加倍效果的影响

为探索河南省新乡市气候条件下玉米单倍体自然加倍的最佳播期,以H847×H865的F1代为基础材料,用孤雌生殖诱导系1089诱导其获得的单倍体为试验材料,采用10个播期(4月27日、5月2日、5月7日、5月12日、5月17日、5月22日、5月27日、6月2日、6月7日、6月12日)分期播种,研究不同播种期对玉米单倍体自然加倍率(显花药率、结实株率)的影响。连续2 a的试验结果表明:不同播期对玉米单倍体自然加倍率的影响有明显差异,4月27日播期的单倍体植株显花药率(57.2%)和结实株率(7.2%)均为最高;其次是5月2日播期,单倍体植株显花药率和结实株率分别为56.7%和6.8%;6月7日播期的单倍体显花药率(12.7%)最低,6月12日播期的结实株率(1.0%)最低;10个播期的单倍体显花药率平均为30.2%,结实株率平均为4.78%。4月27日、5月2日2个播期单倍体的自然加倍率与其他播期相比达极显著差异,表明在当地气候条件下,4月27日—5月2日播种有利于玉米单倍体的自然加倍。     

Increased induction of embryogenesis and regeneration in anther cultures ofSolanum tuberosum L.

Summary A new method is presented for anther culture. Anthers are cultivated on cubes of solid medium, surrounded by liquid medium. This allows changes of media composition at any time. When embryos or callus were produced, the liquid initiation medium was removed and replaced with regeneration medium. The best yield of embryos and the best regeneration frequency were obtained when the initiation medium contained 2,4-dichlorophenoxyacetic acid (2,4-D). Regeneration of shoots from callus was stimulated on double layer medium, with the callus placed on top of a solid medium, partly submerged in the overlaying liquid medium. The best gelling agent for shoot multiplication media was agarose, but gellan gum was a good alternative. Both the production of flower buds and embryogenesis in anther cultures was inhibited by an increased concentration of CO₂ in the air surrounding the donor plants.     

非1B/1R类型和1B/1R类型小麦K型雄性不育系比较研究

利用非 1B/ 1R类型小麦 K型不育系 KTSP3314A和 1B/ 1R类型小麦 K型不育系 K3314A,分别与10个普通小麦品种 (系 ) 2 5 9,36 6 5 ,TB90 2 ,F10 7,J18,R2 0 5 ,L783,5 0 3,3380和 78115杂交 ,测定和比较其恢复性、单倍体发生频率和主要农艺性状。结果表明 ,非 1B/ 1R类型小麦 K型不育系比 1B/ 1R类型小麦 K型不育系更易恢复 ;不育系本身不产生单倍体 ,其杂交种 F1 产生极少或不产生单倍体 ;农艺性状除了株高具有明显的优势外 ,其他均无不利的遗传效应。     

利用小麦与玉米杂交诱导单倍体得胚率的研究

为了更好地利用小麦×玉米单倍体育种技术,利用不同基因型小麦、不同类型玉米,研究单倍体得胚率。结果表明:不同小麦基因型对诱导单倍体胚得频率影响较大,高得胚率达20%,低得胚率仅为3.4%;不同玉米类型对得胚率的影响不同,甜玉米花粉的得胚率高于用普通玉米花粉的得胚率。     

Genetic Inactivation of Stinging Catfish (Heteropneustes fossilis) Sperm with UV Irradiation

To improve the efficiency of gynogenetic induction, the effect of UV light on sperm of Heteropneustes fossilis was optimized. The sperm suspension was diluted to 1 × 10⁷ sperm/ml^?1 in Hank's Balanced Salt Solution. Sperm suspension was irradiated under UV light for different exposure times ranging from 15 to 360 seconds (7500 ergs/mm^?2 for 60 seconds). Sperm motility and egg activation efficiency were assessed for the different exposure durations. Complete inactivation of sperm genetic material was recorded from 120 seconds onwards, and a good motility score was recorded until 240 seconds. A typical “Hertwig effect” in the yield of hatched larvae was observed with doses of UV exposure greater than 75 seconds. Larvae resulting from sperm UV irradiated above 120 seconds were 100% haploid. The genetic inactivation of paternal chromosomes was confirmed by chromosome counting (n = 29) from the resulting embryo, which also had a characteristic haploid syndrome. The resulting embryo (with 29 chromosomes) exhibited haploid syndrome and died after yolk sac absorption.     

A cytological study on aluminium-treated wheat anther cultures resulting in plants with increased Al tolerance

The in vitro selection of microspores and microspore‐derived structures under Al stress is one way to improve the Al tolerance of crops. In our study, cytological alterations caused by Al were examined in anther cultures of a commercial wheat (Triticum aestivum L.) variety ‘Mv Pálma’, and the efficiency of in vitro selection was demonstrated. Although the anther walls retarded the appearance of toxicity symptoms, cytological changes similar to those observed in root cells (inhibition of cell division, intense vacuolisation, occurrence of micronuclei and cell wall thickening) were detected in the microspores. The severity of Al toxicity and the efficiency of selection depended on the Al concentration and the mode of treatment. Single Al treatments (0.6 and especially 1.6 mM) allowed DH lines with increased Al tolerance to be selected. Repeated Al treatment severely inhibited the cell division of the microspores and it was lethal even at a concentration as low as 0.6 mM. The results show that microspore embryogenesis can be exploited for studying the cytological effect of Al and for increasing the Al tolerance of wheat.