亚洲棉、比克氏棉和陆地棉异源四倍体的合成

为了将野生比克氏棉的种子无腺体,而植株上有腺体的珍贵特性转育到栽培棉种上,先用二倍体亚洲棉(A_2A_2)与比克氏棉(G_1G_1)杂交成异源二倍体A_2G_1,将杂种染色体加倍,合成异源四倍体 A_2A_2G_1G_1,再与栽培四倍体陆地棉杂交,组成三交种合成异源四倍体。并对三种杂种的性状遗传学及细胞学进行了分析研究。为培育棉、油、蛋白质三位一体的抗虫新棉种提供了种质。     

Induction of 2n pollen in tulips by arresting the meiotic process with nitrous oxide gas

Triploid tulips have agronomically desirable traits such as vigorous growth and large flower size, but only a portion of all cultivated tulips is triploid. To apply 2n pollen to polyploid breeding of tulips, the polyploidizing agent, nitrous oxide gas (N₂O), was applied to bulbs. In tulips, meiosis in anthers occurs inside the bulbs from mid- to late-October. When meiosis in anthers (excised from bulbs) reached metaphase I, we treated other bulbs of the same clones with N₂O for 24–48 h. Most of the treated plants produced pollen grains with a wide-ranging or bimodal size distribution, indicating a mixture of n, 2n and aneuploid pollen grains. The use of pollen containing a relatively high proportion of giant pollen grains tended to yield larger numbers of triploids in the progeny. The number of giant pollen grains could be increased when N₂O-treated pollen grains were suspended in 10% sucrose and then sieved through a nylon mesh. Very few polyploids were observed in some cross combinations, even those involving pollen with a relatively high proportion of giant grains. Even so, this low polyploid yield most likely is due to a triploid block, because the capsules obtained in the crosses of the diploid×N₂O-treated plants contained some abnormal seeds, which were mostly triploid. Embryo culture was useful in rescuing abnormal embryos. The present study reveals that 2n pollen can be produced at high frequency using N₂O during tulip breeding.     

In vitro tetraploid induction via colchicine treatment from diploid somatic embryos in grapevine (Vitis vinifera L.)

A protocol for in vitro induction of tetraploids via colchicine-treated somatic embryos from immature zygotic embryos of diploid grapevine (Vitis vinifera L.) is reported. Embryogenic callus was initiated from immature zygotic embryos cultured on Nitsch and Nitsch (NN) medium supplemented with 1.0 mg/l 2,4-dichlorophenoxyacetic acid (2,4-D). The callus was transferred to NN medium containing 1.0 mg/l α-naphthalene acetic acid (NAA) and 0.5 mg/l benzyladenine (BA) to establish somatic embryogenesis. The vigorously growing globular embryos were selected and treated by 0, 10 or 20 mg/l colchicine for 1, 2 or 3 days, and then immediately transferred to NN medium supplemented with 0.03 mg/l NAA and 0.5 mg/l BA, for somatic embryo conversion and plant regeneration. The number of surviving embryos and regenerated plantlets following colchicine treatment decreased with increasing colchicine concentration and treatment time. Among 29 randomly investigated plantlets regenerated from colchicine-treated somatic embryos, five solid tetraploids (2n = 4× = 76) were identified by chromosome counting analysis; all others were diploid (2n = 2× = 38). Ploidy level of plant regenerated was also determined from leaves using flow cytometry. No chimeras with both 2C and 4C nuclei was produced from colchicine-treated somatic embryos. Significant differences in leaf stomata parameters were observed between diploid and induced tetraploid plantlets.     

Use of the gene pools of Triticum turgidum ssp. dicoccoides and Aegilops squarrosa for the breeding of common wheat (T. aestivum), through chromosome-doubled hybrids

Summary Triticum turgidum ssp. dicoccoides (wild emmer wheat, AABB, 2n=28) and Aegilops squarrosa (goat grass, DD, 2n=14) comprise a rich reservoir of valuable genetic material, which could be useful for the breeding of common wheat (T. aestivum, AABBDD, 2n=42). Many accessions of both wild species, most of them selected for resistance to stripe rust, were used to make amphiploids. Two strategies were applied: (1) the production of autopolyploid cytotypes of the wild species, followed by hybridisation, and (2) the production of allotriploid interspecific hybrids, followed by doubling of the number of chromosomes. The first route was unsuccessful because of failure of the crosses between the autopolyploid cytotypes, possibly due to incongruity between the two species and to reduced fertility in the autopolyploid cytotypes. The second route yielded the desired synthetic hexaploids. However, the rate of success of the crosses was low and there were great differences between years, and within years between crosses. Embryo rescue was applied to obtain the primary hybrids (2n=21), which were highly sterile and had on average 0.3 bivalents and 20.4 univalents per pollen mother cell. Various abnormalities were recorded. Doubling of the number of chromosomes sometimes occurred spontaneously or was brought about by colchicine treatment. The large scale of the interspecific hybridisation programme ensured that one-third of the female and one-sixth of the male accessions were represented in the synthetic hexaploids.     

浆水芹菜自然和接种发酵过程中有机酸的变化

以芹菜为原料,选用自然和接种发酵处理,测定发酵后有机酸的变化。结果表明:敞口发酵含有酒石酸,并且醋酸含量高;密闭发酵不产生酒石酸而含有苹果酸,醋酸含量低;接种发酵与自然发酵相比,发酵速度快,产生的酸含量高,但产醋酸少。     

油菜倍增计划项目农药类检测与评价以及科学使用

油菜倍增计划里,掌握好除草剂的使用方法是至关重要的。这样才能有效防止病虫害,提高油菜产量。     

氟乐灵诱导南瓜染色体加倍初步研究

以南瓜为试材,通过不同浓度的氟乐灵和秋水仙素进行倍性诱导处理.结果表明,浓度为180 μmol·L-1的氟乐灵具有较好的加倍效果,可以有效代替秋水仙素.和秋水仙素相比,氟乐灵使用的浓度低,价格低廉,效果好,且毒性小,对人和环境比较安全.并用流式细胞仪对南瓜诱导的幼苗进行了倍性分析鉴定.     

含硫油品储罐自燃机理及预防技术研究

介绍了含硫油品储罐自燃机理的研究现状及进展,研究了活性硫对不同类型储罐的腐蚀机理以及硫化亚铁的形成过程.指出事故的原因是由罐的腐蚀产物硫化亚铁氧化放热所引起,提出采用消除石油炼制过程中的硫和将产生的硫化亚铁清洗或转变为其他形式方法,可以预防硫化亚铁的自燃.     

[Hg（SCN）4]^2-配阴离子二级散射和倍频散射光谱法测定蛋白质

在pH=1.0~4.5的稀硫酸介质中,[Hg(SCN)4]2-配阴离子能与人血清白蛋白(HSA)、α-糜蛋白酶(α-Chy)、牛血清白蛋白(BSA)、溶菌酶(Lyso)和γ-球蛋白(γ-G)等蛋白质反应形成复合物,此时将引起二级散射(SOS)和倍频散射(FDS)的显著增强.最大SOS峰和最大FDS峰分别位于668 nm和396 nm附近,散射增强(ΔI)在一定范围内与蛋白质的质量浓度成正比,两种方法对不同蛋白质的检出限(3σ)分别在17.30~43.53 ng/mL(SOS)和18.38~54.04 ng/mL(FDS)之间.据此发展了用SOS和FDS法灵敏、简便、快速测定血清中总蛋白的新方法.考察了共存物质的影响,结果表明该方法具有较好的选择性.