Biomolecular evidence for plant domestication in Sahul

The question of the introduction of domesticated plants from the Sunda plate (South-east Asia) to Sahul (New Guinea, Australia and Tasmania) has been a subject of speculation and debate for decades. This paper reviews recent phylogenetic studies conducted with biomolecular markers on bananas (Musa spp.), breadfruit (Artocarpus altilis), sugarcane (Saccharum spp.), taro (Colocasia esculenta) and the greater yam (Dioscorea alata). Biomolecular evidence for plant domestication in Sahul is presented and discussed. Biomolecular markers reveal that for these crops at least, domestication has occurred in New Guinea and further east in Melanesia. This domestication produced cultivated genotypes that were selected from the endemic wild gene pools. These areas of domestication still are important centres of diversity for crop species that also exist in Asia. For most crops, genetic distances are very important between the two gene pools due to the geographic isolation of the two continental plates. The implications of these findings have obvious bearings on genetic resources programme strategies and future surveys.     

银法利悬浮剂防治槟榔芋疫病田间药效试验

进行了68.75%银法利悬浮剂对槟榔芋疫病的田间防效试验。试验结果表明,68.75%银法利悬浮剂对槟榔芋疫病有较好的防治效果。在疫病发生初期用70%安泰生可湿性粉剂500倍液喷施1次,发生高峰期用68.75%银法利悬浮剂500倍液或600倍液喷施2次,在第3次药后7d防治效果分别为73.91%和68.82%,第3次药后14d防治效果分别为69.86%和65.36%,且对槟榔芋生长无不良影响。     

激素配比与茎尖大小对甘薯脱毒苗培育的影响

[目的]研究激素配比与茎尖大小对甘薯脱毒苗培育的影响。[方法]以高淀粉甘薯品种湘福1号和美国SL-9为材料,进行甘薯脱毒苗培育试验。[结果]湘福1号在MS+0.8 mg/L 6-BA+0.2 mg/L NAA+0.05 mg/L GA3培养基中,愈伤组织生长最快,成苗率最高,1次培养成苗率比转移的2次培养成苗率高24.5%,秧苗素质也好;美国SL-9茎尖所带叶原基越多,则成苗率越高,脱毒率越低。[结论]综合成苗率与脱毒效果认为,以带2个叶原基的茎尖在含有激素的培养基中的培育效果最好。     

木薯叶片染色体制片技术研究

以木薯嫩叶为材料,对其染色体制片技术的取样时间、预处理药剂、固定液、解离方法以及染色剂等方面进行了试验研究。结果表明：取材时间为上午8：30~10：00,用0.1％秋水仙素与0.002 mol/L 8-羟基喹啉混合液室温预处理 3 h,经固定液（无水酒精 ∶ 氯仿 ∶ 冰醋酸=6 ∶ 3 ∶ 1）固定,用1 mol/L盐酸60 ℃下解离8 min,再用改良苯酚品红染色压片镜检,能取得良好的分裂相效果。     

海蛰的生殖与受精——1.排卵方式的探讨

作者对海蛰卵巢进行了解剖、组织切片与扫描电镜观察,发现卵巢为褶叠型,一端与胶质膜相连,另一端游离。胶质膜由透明状胶质细胞所构成,外有一层纤毛细胞,靠近胶质膜一侧的卵巢为单层上皮组成的生殖上皮,胶质膜与卵巢生殖上皮间由胶质细丝连接,形成与胃腔相通的生殖腔隙。生殖上皮在生殖季节中变化很大,它首先完成发生卵原细胞的功能,随后局部解体出现透明小区,当卵巢成熟时生殖上皮细胞是区域性弥散,卵子裸露,出现分批排卵现象.海蛰排卵方式是以大量卵子成片分批区域性排放为主,但也存在单个卵子排出的现象。     

羊肚菌固体发酵转化厨余垃圾制取饲料的研究

厨余垃圾的无害化处理与资源化利用是我国生活垃圾处理的重要方面。为探索羊肚菌转化厨余垃圾制取饲料的最佳工艺,进而实现厨余垃圾的饲料化利用,利用食用蕈菌羊肚菌对厨余垃圾进行了固体发酵实验。结果表明,当厨余垃圾和辅料豆渣按11质量比混合,发酵时间为20d,发酵温度为25℃,pH在自然状态下,含水率为65,接种量为15时,饲料中粗蛋白质含量提高幅度最大,最终含量都在20以上,且粗脂肪含量均小于17,粗纤维含量小于16,符合国家蛋白饲料标准的要求。     

昆嵛山萱草属植物细胞学研究及其应用分析

研究了两种来自昆嵛山萱草属(H.emerocallis)植物的染色体数目、核型,结果表明:黄花菜(H.citrina)的体细胞中期染色体核型:2n=2X=22=16m+4sm+2T,核型不对称系数为58.9%,染色体相对长度组成:2n=2X=22=6L+10M1+6S,染色体总体积为105.39μm3;北萱草(H.esculenta)体细胞中期染色体核型:2n=2X=22=20m+2T,核型不对称系数为53.8%,染色体相对长度组成:2n=2X=22=4L+2M2+14M1+2S,染色体总体积为99.43μm3。同时对染色体的性状进行了巢式方差分析,表明居群内个体间、细胞间染色体的形态和大小具有一定程度的变异,且居群内的变异主要来自于个体间;最后分析了该属植物的应用前景。     

氮钾配施对芋头产量和品质的影响

采用二次饱和D-最优设计,研究了氮钾肥配施对芋头产量和品质的影响,并建立了以氮、钾肥施用量为变量因子,芋头产量和品质为目标函数的二元二次数学模型。模型解析表明,氮、钾肥对芋头产量和品质均有显著影响,且钾肥的影响大于氮肥;氮、钾肥之间存在显著的交互效应。在氮(N)、钾(K2O)施用量分别为261.75kg/hm2、757.50kg/hm2以内,产量随施肥量的增加逐渐提高,超过此施用量,则产量下降。在本试验条件下,施肥量为N34.5～531.0kg/hm2,K2O.526.8～1057.2kg/hm2,芋头产量可达30000kg/hm2以上。     

崇明芋花叶病毒病的初步鉴定

芋花叶病毒病是造成天星科植物产量下降,品质劣变的主要原因。作者通过田间调查、电镜负染和核酸斑点杂交的方法,分析了崇明特产品种崇明香酥芋和崇明县主栽品种浙江红梗芋芋花叶病毒病(Dasheenmosaicvirus,DMV)的发病情况,初步推断崇明县境内芋艿已被芋花叶病毒侵染,并探讨了用茎尖分生组织培养生产脱除DMV种苗的必要性。     

Genetic potential and stability of carotene content in cassava roots

People in vast areas of the tropics suffer from vitamin A deficiency, resulting in progressive eye damage and eventually leading to blindness. Improving the content of vitamin A precursors in staple crops could alleviate or solve such a problem. The objective of this work was to study the range of variability for carotene content in a sub-set of the global cassava germplasm collection, and to determine the inheritance of carotenes, as well as their stability in response to different processing methodologies. Genotypes with more than 2 mg carotenes/100 g of fresh roots have been selected as parental material for population development. Although root colour is highly correlated with carotene content, a quantitative evaluation of genotypes selected by colour is required in order to increase the efficiency of selection. Relatively few major genes are involved in the determination of carotene accumulation in cassava roots. Stability of carotenes in response to different processing methods is genotypically dependant, representing a trait to be evaluated after selecting for high carotene concentration in fresh roots. The results from this work have provided the basis for defining future strategies for the improvement of the nutritional quality of cassava. This revised version was published online in July 2006 with corrections to the Cover Date.