杂交鹅掌楸胚性细胞悬浮系的建立

通过对影响悬浮培养的一些物理因素如摇床转速、细胞起始密度等的研究,建立了良好的杂交鹅掌楸胚性细胞悬浮系.研究表明,当摇床转速为100 r/min,细胞起始密度为1×103～3×103个/mL时,可建立一个均匀性、分散性较好和细胞增值较快的杂交鹅掌楸胚性细胞悬浮系.悬浮细胞系的继代周期以2～4周为宜.培养效果最好的悬浮物是直径介于150～280 μm的细胞团,其干重占总悬浮物干重的65%.     

离子束对甘薯胚性悬浮细胞团的辐射诱变效应

以甘薯品种栗子香为材料,用0～100 Gy 12C5+和0～200 Gy 4 He2+离子束分别照射其胚性悬浮细胞团,结果表明栗子香胚性细胞团适宜的12C5+和4He2+辐射剂量分别为30～50 Gy和50～70 Gy。对辐照后的材料进行培养,通过体细胞胚胎发生途径获得大量再生植株。将获得的再生植株移栽到大田,对其地上部和地下部特征进行分析,发现离     

野生阿宽蕉胚性细胞悬浮系原生质体分离及植株再生

本研究以野生阿宽蕉(Musa itinerans Cheesman)未成熟种子诱导的胚性细胞悬浮系为材料,对其原生质体的分离和植株再生进行研究。结果表明:胚性悬浮细胞在酶组合:3.0%纤维素酶R-10、1.0%离析酶R-10、0.2%果胶酶Y-23、1.52%KCl、0.78%CaCl2、0.01%MES和11%甘露醇中,酶解8h,原生质体的产量和活力达到最大值,分别为19.46×106个/mL和92.17%。采用看护培养法对原生质体培养60d后,可获得大量增生的小细胞团,细胞团悬浮培养15d后转至体胚诱导培养基上培养约30d,其体胚萌发率为45.97%,然后转至生根培养基上培养35d,其再生植株率为54.76%。     

甘薯体细胞胚的发生和植株再生

利用含不同浓度2,4-D的修改的MS培养基对7个甘薯(Ipomoea batatas Lam.)品种进行茎尖脱毒培养,产生了形态和解剖特征明显不同的3种愈伤组织,胚性愈伤组织的诱导频率与品种和2,4-D浓度有关。将胚性愈伤组织转移到不含激素的修改的MS培养基上,有3个品种的胚性愈伤组织进一步发育成鱼雷胚和子叶胚。其中高淀粉品种苏薯2号的子叶     

悬浮培养条件下体细胞胚发育的同步化控制

利用液体悬浮培养体系进行体细胞胚的大规模生产,被认为是21世纪最具发展潜力的生物技术之一.但是,大多数体胚发生系统都存在发生频率低、同步化程度不高等问题,这在很大程度上限制了体胚发生和人工种子技术在生产上的应用.本文论述了体胚发生不同步的原因,重点介绍了悬浮细胞培养过程中同步化控制的方法和检测手段,提出了利用液体悬浮培养体系进行同步化控制的研究方向.     

“Gros Michel”香蕉胚性细胞悬浮系及遗传转化体系的建立

本研究以"Gros Michel"香蕉未成熟雄花序为外植体,建立了其胚性细胞悬浮系及遗传转化体系。结果表明,90 d后可诱导产生浅黄色松散的胚性愈伤组织,经悬浮培养120 d后获得含有均质细胞团的胚性细胞悬浮系(ECS);将3个月龄的ECS置于胚诱导培养基30 d后有大量白色半透明状球形的体细胞胚发生,继代培养60 d后发育为成熟不透明的体细胞胚;将成熟的体胚在萌发培养基上培养10 d后有幼芽产生,转移至生根培养基30 d后得到幼苗。同时开展了含绿色荧光蛋白(GFP)的pCAMBIA0380载体的遗传转化研究,经过3次液体培养基筛选转移至半固体筛选培养基90 d后,在胚萌发培养基和生根培养基中不再添加抗生素。经对转化植株的根尖镜检及PCR鉴定,均为阳性植株。研究结果将为进一步开展"Gros Michel"优质抗病基因功能研究提供材料和技术支撑。     

黑麦胚性悬浮细胞系的建立和植株再生

禾谷类作物胚性细胞悬浮系的相继建立,为获取大量原生质体、进行体细胞杂交和将外源DNA直接导入可再生细胞（贾敬芬,1990）奠定了坚实基础。黑麦是重要的禾谷类作物之一,具有耐酸、耐瘠、耐旱、耐寒等许多优良特性（李杨汉,1979）。为利用细胞工程技术对黑麦进行改良和将其优良性状转移到其它禾谷类作物中,建立可高频再生的黑麦胚性细胞悬浮系十分必要。本文报道了黑麦胚性悬浮细胞系建立和植株再生的实验结果。     

水稻胚性悬浮细胞系建立过程中的生理生化变化

本文详细分析了水稻广亲和中粳品系０２４２８胚性悬浮细胞系建立过程中的培养液渗透值、ＰＨ值，呼吸作用，过氧化物酶同工酶，碳、氢及矿质元素的变化。结果如下：１、前期、中期和后期悬浮细胞系（好胚性悬浮细胞系）的培养液渗透值在一次继代培养的０－３天期和后期悬浮细胞比前期悬浮细胞更多地利用氨基酸作为代谢底物。后期悬浮细胞的ＥＭＰ途径相对稍低，而ＨＭＰ、ＴＣＡＣ途径较前期、中期稍强。３、从前期－中期－后期，过     

甘薯体细胞胚状体及其在脱毒、扩繁中的应用

通过甘薯徐薯18茎尖体细胞培养诱导胚性愈伤组织和胚状体,建立了体细胞无性系.胚性愈伤和胚状体诱导培养基为MS附加0.5～2.0mg/L 2,4-D、0.5mg/L NAA、0.1mg/L BA及100mg/L HL.研究结果表明:采用茎尖体细胞胚胎发生途径能够同时实现试管苗的深度脱毒及大幅度提高扩繁量,脱病毒率达95%,扩繁量达382.9倍.田间种植该脱病毒种苗能     

甘薯（Ipomoea batatas (L.) Lam.）及其近缘野生种原生质体的植株再生

对甘薯品种高系14号及其近缘野生种I.triloba L、和I.lacunosa L,进行原生质体植株再生研究。从离体培养植株的叶柄分离出原生质体,将其培养在含有0.05mg/L 2,4-D和0.5mg/L激动素(KT)的MS培养基中,从原生质体获得了高频率的愈伤组织。培养8-12周后,将直径达2—3mm的小愈伤组织转移到添加0.05mg/L 2,4-D的MS培养基上。转移3-6周后,将愈伤组织进一步转移到添加吲哚乙酸(IAA)和6-苄基嘌呤(BAP)的MS培养基上,一些愈伤组织再生出植株。未再生植株的愈伤组织进一步在MS基本培养基上培养,它们也再生出植株。本研究从I.triloba原生质体获得高频率的植株再生;首次从I.lacunosa原生质体再生出植株;从高系14号原生质体也再生出完整植株。     

甘薯和Ipomoea lacunosa的种间体细胞杂种植株再生及鉴定

用ＰＥＧ融合法融合甘薯品种高系１４号和近缘野生种Ｉｐｏｍｏｅａ ｌａｃｕｎｏｓａ的原生质体,将融合原生质体培养在含有０．０５ｍｇ／Ｌ２,４－Ｄ和０．５ｍｇ／Ｌ ＫＴ的ＭＳ培养基上,愈伤组织迅速增殖。将其中的７０个愈伤组织培养在添加３．０ｍｇ／Ｌ ＢＡＰ的ＭＳ培养基上,并进一步培养在ＭＳ基本培养基上,获得９株再生植株。过氧化物酶同工酶、酯酶同工酶和ＲＡＰＤ分析表明,其中２株再生植株（ＫＬ１和ＫＬ３）     

Response of Sweet Potato (Ipomoea batatas L.) to Different Planting Times

Agricultural seasons of the tropics are associated with rainfall, which provides the principal limiting resource for crop production. However, as tuber crops are sensitive to temperatures and moisture, the time of planting could have a profound influence on yields. Thus a study was carried out over a period of 12 months to determine the effect of different planting times on establishment, tuber initiation and yields of sweet potato. The trial was planted on similar soils in two agroecological zones as this species is a popular home garden crop in most regions of the tropics and subtropics.
Planting sweet potato with the onset of rains in October produced the highest yields. This is attributed to the receipt of adequate rainfall over the growth cycle, along with the higher diurnal variation in temperatures. Planting in the dry season or later in the wet season, which receives a lower quantity of rainfall with low diurnal variations in temperatures delayed tuber initiation and reduced yields. The study highlights differences in growth patterns of sweet potato when planed at different times. The importance of planting sweet potato in agricultural systems at appropriate times to produce higher yields is presented.     

Response of Sweet Potato (Ipomoea batatas Lam.) to Shading at Different Growth Stages

During 1990 and 1991 growth seasons at two locations in Peru four sweet potato cultivars were tested for their response to a short-term shading. The plants were subjected to artificial shade (42 % light reduction) for 1 month at different growth stages.
A high genetic variability was found in the extent to which tuber and total biomass yield of sweet potato was affected by sub-optimal light conditions. One cultivar was completely tolerant to shade at all growth stages, whereas the others showed a yield decline between 20 % and 55 %. Generally tuber yield was most reduced when shade was imposed at the end of the growth season (fourth and fifth months) and the least at its beginning (first and second months). Yield losses were due to a diminished biomass production and/or an altered assimilate partitioning within the plant. Tuber formation was affected rather than tuber initiation.     

The Response of Sweet Potato (Ipomoea batatas Lam.) to Inter- and Relay-cropping with Maize (Zea mays L.)

Four sweet potato cultivars were inter- and relay-cropped with maize at two locations in Peru. Increasing interspecific competition drastically reduced tuber yields of all cultivars; fewer tubers m ⁻² were produced and no tolerant genotype was identified. Likewise the mean tuber weight declined linearly for two cultivars when competition became severe. Shoot development was less affected. Under intense competition the plant top was favoured in assimilate partitioning to the detriment of tuber formation. Overall reduction in assimilate production due to mixed cropping was the major cause of yield loss. Various intercropping combinations were found with the same productivity but distinct proportions of the component crops (sweet potato + maize). Land equivalent ratio (LER) exceeded sole crop productivity only for the combinations with the highest maize yields. Biomass production was clearly increased by intercropping but there was no increment in marketable yields. Relay-cropping reduced tuber and maize yields and had the lowest productivity of all combinations tested.     

土壤干旱对甘薯生育及产量的影响

利用甘薯品种郑红５号和徐薯１８研究了土壤干旱对甘薯生育和产量的影响。结果表明，生长前期（栽后０～６０天）叶片数、叶面积、茎长及其相应的干旱胁迫指数均随土壤干旱程度的加重而相应减少，薯块的形成和膨大也受到严重影响。当土壤含水率在６％～１０％范围内，６～８月各月份进行的干旱处理与对照（全期湿润）相比，其鲜薯产量差异均达极显著水平。干旱指数为６月＞７月＞８月＞９月。前期干旱比后期干旱对鲜薯产量影响较重。据此，提出了甘薯旱地栽培应充分利用自然降水及水浇地栽培经济用水的技术措施。     

荔枝胚性悬浮细胞系的快速建立及其体胚植株的再生

荔枝幼胚诱导的胚性培养物在低糖条件下连续继代4~6次左右,可筛选到颗粒细小、不含原胚的松散型胚性愈伤组织;以这种松散的胚性愈伤组织作为起始材料,在附加2,4-D 2mg/L或2,4-D 2mg/L、KT1 mg/L、AgNO3 5mg/L的MS液体启动培养基上振荡培养（100~120 r/min）10~14 d,即可建立起分散性良好的胚性悬浮细胞系。采用激素减半的2种启动培养基交替继代培养或周期性固体－液体轮回培养,可以长期保持胚性悬浮细胞系。荔枝胚性悬浮细胞在附加NAA 0.1 mg/L、KT 或Ze 5 mg/L、肌醇100 mg/L、蔗糖50g/L、琼脂10g/L的MS固体培养基上诱导体胚,25~40d后可形成大量胚状体,诱导体胚数量达10,000个/g FW以上。经过成熟培养后,正常的体胚75%以上萌发再生完整植株。     

Plant regeneration in sweet potato (Ipomoea batatas L., Convolvulaceae)

The application of new techniques for improvement of sweet potato crops, particularly including the exploitation of somaclonal variation, gene transfer by genetic transformation and somatic hybridization, requires the control of plant regeneration from tissue cultures. Shoots can easily be regenerated from explants of stems, petioles, leaves and roots, while callus cultures do not produce any shoots. The potential of somatic embryogenesis and plant regeneration via embryogenesis was evaluated for 10 cultivars of sweet potato. Protocols for plant regeneration from cultured protoplasts have also been developed. Since mesophyll was resistant to enzyme digestion, fragments of stems and petioles, callus and cell suspensions were used as source of protoplasts of sweet potato. Series of transfers of protoplast-derived calluses, particularly those which had been obtained from in vitro plants, to media containing a high level of zeatin resulted in successful formation of shoots in only two sweet potato cultivars. In addition, the embryogenic potential was irreversibly lost through protoplast culture, since protoplasts isolated from embryogenic cell suspensions developed into non-embryogenic callus. Consequently, an alternative protocol is being successfully developed to improve plant regeneration from cultured protoplasts of sweet potato, involving first root formation from which shoots can then be regenerated. Preliminary evaluation in field conditions in Gabon revealed that plants regenerated from cultured protoplasts exhibited a great genetic variability in their growth and tuber formation in particular. This revised version was published online in July 2006 with corrections to the Cover Date.     

水分胁迫对甘薯叶绿素荧光和光合特性的影响

以甘薯品种皖84-559，徐州18，为材料，测定功能叶片的光合和叶绿素荧光参数的变化。水分胁迫下，徐州18叶绿素含量、光合速率、PSⅡ原初光化学效率（Fv/Fm）和光化学猝灭系数（qP）的下降较少；非光化学猝灭系数（qN）增加较少。表明徐州18在水分胁迫条件下，光合机构受破坏较轻，其吸收的光能能较多的用于光化学转化能力，通过热耗散的能量较少。