甘蓝小孢子单倍体植株加倍技术探讨

【目的】比较甘蓝单倍体植株(H植株)茎生叶及其愈伤组织的秋碱处理时间及愈伤组织大小对再生植株加倍效果的影响,筛选加倍效果最佳的秋碱处理时间与合适的外植体,为扩大甘蓝小孢子双单倍体植株(DH株)群体及提高甘蓝小孢子培养效率奠定基础。【方法】以3个甘蓝H植株(H10-23,H10-3和H10-5)的茎生叶为试材,用2.0mg/L秋碱溶液浸泡处理H植株叶片外植体及其愈伤组织以获得再生DH植株,设置15,30和60h3个处理时间,比较分析秋碱处理叶片外植体和愈伤组织的时间对加倍效果的影响;同时用2.0mg/L秋碱溶液处理大(直径≥1cm)、中(1cm直径≥0.5cm)、小(直径0.5cm)3种类型的愈伤组织30h,比较愈伤组织大小对加倍效果的影响。【结果】2.0mg/L秋碱处理甘蓝单倍体植株叶片外植体30h,可获得44.80%的平均再生DH株加倍率;2.0mg/L秋碱处理愈伤组织30h,可获得58.13%的平均再生DH株加倍率;2.0mg/L秋碱处理中等大小的愈伤组织30h,可获得51.11%的再生DH株加倍率。【结论】用2.0mg/L秋碱处理甘蓝H植株茎生叶及其愈伤组织30h,可获得较高比例的DH株。     

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.     

甘蓝型油菜DH系的SSR遗传多样性研究

由甘蓝型油菜杂交组合青油14号×四达和北山繁×46号的F1植株通过小孢子培养所获得的DH(doubled haploid)群体中,各随机选择31个DH系,分别编号为:1～31,32～62,采用SSR标记对其进行遗传多样性分析.30对SSR引物分别扩增出82、80个多态性片段,其中多态性位点各占总扩增位点的75.2%和74.1%,片段大小介于120～900 bp间.每对引物在不同DH系间的等位基因数在2～9间,平均位点为3.63个.1～31 DH系PIC(位点多态性信息含量)变幅为0.06～0.85,平均为0.60;32～62 DH系PIC变幅为0.06～0.86,平均为0.56.遗传距离分布频数分析表明,两个组合DH系之间的遗传距离分布在>1.0范围内的频数都超过了30%(分别为37%和34.4%).对SSR扩增结果进行UPGMA分析,在0.66处可将62个DH系聚为四大类.以上结果表明,通过小孢子培养获得的DH系遗传多样性比较丰富,且不同组合的DH系基因型多样性不同.     

利用分子标记定位水稻芽期耐冷性基因

 利用籼稻品种南京11和粳稻品种巴利拉的F₁花药进行组织培养,获得67个加倍单倍体植株(Doubled haploid, DH)。 以该群体构建了一张包含131个RFLP标记的水稻分子图谱。 以芽期的死苗率为指标, 评定亲本及各 DH系在低温(4～5℃)条件下的耐冷性。结果表明：死苗率在DH群体中呈双峰连续分布, 表明芽期耐冷性是由主基因控制的数量性状。将死苗率作为数量性状进行QTL的区间作图分析, 发现在第7染色体上G379b-RG4区间存在有与耐冷性有关的基因(Cts7) 。     

Low relative humidity increases haploid production in durum wheat X maize crosses

Haploidization is a useful tool for genetic analysis and plant breeding, but a consistent and satisfactory protocol for haploid production has been difficult to achieve in durum wheat. The objective of this study was to analyze the influence of the relative humidity of the environment, when culturing detached tillers during the production of haploids plants in durum wheat by the maize method. Thirty‐eight F3 lines from eight crosses of durum wheat were pollinated with bulked pollen from three commercial maize hybrids. A mixture of 2‐4D and dicamba was used as a hormone treatment. The numbers of caryopses, embryos and haploids plants were scored. When 65‐85% (light‐dark) humidity was substituted for 55‐65% the number of haploids per spike increased notably. This increased frequency was largely attributed to a rise in the production of generated caryopses. On average, 15.2 vs. 9.3 caryopses, 5.0 vs. 2.8 embryos, and 3.1 vs. 0.6 haploid plants, per spike, were produced under low and high humidity regimes, respectively.     

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。     

秋水仙素和除草剂浸芽加倍玉米单倍体效率的研究

以Mo17× PHB1M诱导的单倍体子粒为试验材料,利用戊炔草胺、甲基胺草磷和秋水仙素为加倍药剂,浸芽处理单倍体种子.结果表明:戊炔草胺质量浓度为4～16 mg/L时的加倍率为5％～16％;甲基胺草磷质量浓度为8～32 mg/L时的加倍率为8％ ～ 16％;秋水仙素质量浓度为0.4～1.0 mg/L时的加倍率为5.5％ ～16.5％,3种药剂对玉米单倍体加倍均有效果.其中8 mg/L的戊炔草胺、21 mg/L的甲基胺草磷、0.7 mg/L的秋水仙素浸芽8h的玉米单倍体加倍率均为各组最高.戊炔草胺和甲基胺草磷可以替代秋水仙素加倍玉米单倍体.     

甘蓝型油菜开花期的QTL定位及候选基因鉴定

为了解析油菜开花期性状的遗传机制,利用KN DH群体在冬性、半冬性和春性环境的开花期表型和KN 高密度遗传连锁图谱,通过Wincart 2.5软件的符合区间作图法对油菜开花期性状进行QTL定位及候选基因鉴定。结果显示,共鉴定到119个开花期QTL,单个QTL解释表型变异最大是qFT-13DL16-4 （25.96%）,最小的是qFT-13ZY2-1（2.48%）。利用元分析的方法将初步鉴定的QTL整合为consensus QTL,共获得26个环境稳定表达QTL,包括7个开花期主效QTL。如cqFT-A2-3、cqFT-A2-4在春性环境稳定表达,cqFT-C6-4、cqFT-C6-7、cqFT-C6-12、cqFT-C6-13在冬性和半冬性环境稳定表达, cqFT-C6-14在冬性环境稳定表达QTL。主效QTL置信区间共鉴定到15个与成花诱导相关的候选基因,如 BnaA02g12260D（RGA1）、 BnaA02g15390D（AGL12）、 BnaA02g16710D（LKP2）和BnaC06g19930D（NUA）等,这些候选基因主要涉及赤霉素、光周期、生物钟、春化作用响应和花发育等功能。可见,油菜开花期主效QTL及其候选基因的鉴定为开花期基因的精细定位和图位克隆奠定基础,也为培育早熟、高产油菜品种提供指导。     

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。     

Properties of maternal haploid maize plants and potential application to maize breeding

Summary Presented are the results of a two-year study of haploid maize plants in the field. The haploids were produced with the aid of inducer line ZMS. In total, 604 and 1030 haploids were obtained and studied in the first and second years, respectively. Tassels of haploid plants were found to be almost completley sterile. Fertility of ears was studied by pollinating them with the pollen from diploid inbred lines, the cross resulting in almost all of the haploid ears carrying kernels. On average 27.4 kernels per ear of haploid plant were obtained in the first year of study and 26.3 in the second. These gave rise to normal diploid plants. This property allows genotypes selected at the level of haploid plants to be involved in breeding process. Unusual plants were found among haploids, phenotypically resembling homozygous lines. It was assumed that the plants had resulted from spontaneous chromosome doubling in haploids. The results of comparative studies of progenies of unusual plants and inbred lines derived from the same synthetic population are presented.