藏酋猴的分类与分布

本文基于外部形态,毛色,头骨特征和地理分布对藏酋猴进行了分类整理,认为藏酋猴在不同地理区域之间的差异已达到了亚种水平,可分为４个亚种（包括两新亚种）：Ｍ．ｔｈｉｂｅｔａｎａｔｈｉｂｅｔｎａ,Ｍ．ｔｈｉｂｅｔａｎａｐｕｌｌｕｓ．Ｍ．ｔｈｉｂｅｔａｎａｈｕａｎｇｓｈａｎｅｎｓｉｓｓｕｂｓｐ．ｎｏｖ．和Ｍ．ｔｈｉｂｅｔａｎａｇｕｉｚｈｏｕｅｎｓｉｓｓｕｂｓｐ．ｎｏｖ。     

The effect of genome and sex on recombination rates in Pennisetum species

The effects of homoeology and sex on recombination frequency were studied in crosses between cultivated pearl millet, Pennisetum glaucum, and two wild subspecies, P. violaceum and P. mollissimum. For the two wild x cultivated crosses, reciprocal three-way crosses were made between the F₁ hybrid and an inbred line (Tift 23DB₁). The three-way cross populations were mapped to produce a female map of each wide cross (where the F₁ was the female) and a male map (where the F₁ was the male). Total genetic map lengths of the two inter-subspecies crosses were broadly similar and around 85 % of a comparable intervarietal map. In the P. glaucumxP. mollissimum crosses, the map was further shortened by a large (40 cM) inversion in linkage group 1. Comparison of the recovered recombinants from male and female meiocytes showed an overall trend for the genetic maps to be longer in the male (10%) in both inter-subspecific crosses; however, analysis of individual linkage intervals showed no significant differences. Gametophytic selection was prevalent, and sometimes extreme, for example 121 in favour of wild alleles in the P. glaucumxP. mollissimum male recombinant population. One of the loci which determines panicle type in cultivated pearl millet and wild relatives, H, was mapped 9 cM from Xpsm812 on linkage group 7 in the P. violaceum cross.     

Microsatellite DNA markers for rice chromosomes

We found 369 complete microsatellites, of which (CGG/GCC)_n was the most frequent, in 11 798 rice sequences in the database. Of these microsatellites, 35 out of 45 could be successfully converted into microsatellite DNA markers using sequence information in their flanking regions. Thus, the time and labor used to develop new microsatellite DNA markers could be saved by using these published sequences. Twenty eight polymorphic markers between Asominori (japonica) and IR24 (indica) have been correctly mapped on the rice genome and microsatellites appear to be randomly distributed in the rice chromosomes. Integration of these markers with the published microsatellite DNA markers showed that about 35% of the rice chromosomes were covered by the 56 microsatellite DNA markers. These microsatellites were hypervariable and were easily to assay by PCR; they were distributed to all chromosomes and therefore, one can easily select plants carrying desired chromosome regions using these microsatellite DNA markers. Thus, microsatellite maps should aid the development of new breeds of rice saving time, labor, and money.     

RFLP-based maps of the homoeologous group-6 chromosomes of wheat and their application in the tagging of Pm12, a powdery mildew resistance gene transferred from Aegilops speltoides to wheat

Genetic maps of the homoeologous group-6 chromosomes of bread wheat, Triticum aestivum, have been constructed spanning 103 cM on 6A, 90 cM on 6B and 124 cM on 6D. These maps were transferred to a Chinese Spring (CS) x line #31 cross to locate a dominant powdery mildew resistance gene, Pm12, introgressed into line #31 from Aegilops speltoides. Pm12 was shown to lie on the short arm of translocation chromosome 6BS-6SS.6SL in line #31, but could not be mapped more precisely due to the lack of recombination between the 6S Ae. speltoides segment and chromosome 6B. Possible strategies to reduce the size of the alien segment, which probably encompasses the complete long arm and more than 82% of the short arm of chromosome 6B, are discussed.     

Sex influence on recombination frequency in Secale cereale L.

The variation in recombination frequency (rf) is important to plant breeders since their major objective is to obtain favorable recombinants of linked genes. One source of variation in rf is sex. Sex differences for recombination frequencies were studied in four of the seven chromosomes of Secale cereale L. cv Ailés using isozyme and storage protein loci and were determined on the basis of reciprocal crosses between heterozygous plants of cv. Ailés and homozygous plants of the inbred line Riodeva. The differences were found to be strongly segmentspecific. In some cases the level of crossing-over in male and female meiosis was about the same (between Pgm1 and Ndh1 loci on chromosome arm 4RS). However, for most of the chromosome segments in 1R, 3RL and 6RL the male rf was significantly higher than the female rf. Different hypotheses about the mechanisms of plant sex differences for recombination are discussed.     

八角科植物的地理分布

本文依据八角科的系统分类和地理分布,结合古植物、古地理和古气候资料,分析和推论八角科的起源地点在劳亚古陆,很可能是在劳亚古陆中南部的温暖湿润山地。八角科的起源时间早于白垩纪末期,很可能在白垩纪中期。八角科的迁移扩散途径是沿山地进行,从西欧进入北美,从北往南,从内陆往沿海。世界现代八角科植物是以东亚成分为主,东亚的横断山至华东一带（２０—３０°Ｎ,９８—１２３°Ｅ）为八角科的现代分布中心、现代分化中心和东亚八角科现代原始类群分布中心。八角科曾为古热带湿润山地分布型,现代为东亚－北美分布型;现代分布格局形成的原因在欧美是因为海浸和冰川作用,在亚洲则是寒化（冰川）和旱化的综合作用,而物种丰富程度则是由于东亚较北美有更多的地理隔障机制。     

南亚和东南亚巨蜥居群的种间亲缘和越南─新种描述

１９９２年１１月１５日从云南省河口县城自由市场的一位越南人手中买得一雌性巨蜥,经鉴定为一新种,定名为越南巨蜥Ｖａｒａｎｕｓｖｉｅｔｎａｍｅｎｓｉｓ。鉴别特征：新种背部鳞片光滑,仅在后半部插有极少的起棱鳞片,不同于Ｖ．ｎｅｂｕｌｏｓｕｓ（Ｂｏｕｌｅｎｇｅｒ,１８８５,１８９０;Ｔａｙｌｏｒ,１９６３）;新种不同于Ｖ．ｓａｌｖａｔｏｒ在于其背部没有眼斑状横斑带（ｏｃｅｌｌｉｍａｒｋｓ）（Ｇｕｅｎｔｈｅｒ,１８６４;Ｈａｒｒｉｓｏｎ等,１９５７;Ｐｏｐｅ,１９３５）;不同于Ｖ．ｉｒｒａｗａｒｄｉｃｕｓ（Ｙａｎｇ等,１９８７）,Ｖ．ｇｒｉｓｅｕｓ和Ｖ．ｍｏｎｉｔｏｒ（Ｓｍｉｔｈ,１９３５）在于有６─７个横向扩大的眼上鳞。文中运用了１５个外部性状对产于南亚,东南亚大陆及岛屿共９个种（含新种）的种间亲缘关系进行了研究,结果认为,种间亲缘关系的亲疏与分布地区相距的远近成正相关。     

Survey ofFusarium species in an arid environment of Bahrain

The prevalence and distribution of soil-inhabitingFusarium species in the soil of vegetable crops grown under custom-made plastic tunnels were studied at three geographical locations on the island of Bahrain. Six species ofFusarium representing a total of 1154 isolates were isolated on modified Komada medium. All species reported in this survey are recorded for the first time from the hot, arid desert of Bahrain.Fusarium solani andF. oxysporum were among the most frequently isolated fungi in all locations and crops.     

含金地质体表生带中主要微生物类群的研究

通过对16个含金矿区主要微生物类群的分布、生态结构的研究,发现不同类型的金矿具有不同的微生物类群.金矿矿石与金矿酸水中的自养硫细菌和异养菌分布具有明显差异,酸性水中含自养硫细菌较多,含异养菌极少;金矿氧化带中的异氧菌一般多于自氧硫细菌,其优势菌以芽孢杆菌属中蜡状芽孢杆菌为主.研究结果揭示了金矿中存在的主要微生物类群,对阐明表生金的形成、成岩和蚀变作用具有一定的意义,对发掘生物湿法冶金菌种资源具有重要作用.     

The new class 11 transposon Tn163 is plasmid-borne in two unrelated Rhizobium leguminosarum biovar viciae strains

Tn163 is a transposable element identified in Rhizobium leguminosarum bv. viciae by its high insertion rate into positive selection vectors. The 4.6 kb element was found in only one further R. leguminosarum bv. viciae strain out of 70 strains investigated. Both unrelated R. leguminosarum bv. viciae strains contained one copy of the transposable element, which was localized in plasmids native to these strains. DNA sequence analysis revealed three large open reading frames (ORFs) and 38 bp terminal inverted repeats. ORF1 encodes a putative protein of 990 amino acids displaying strong homologies to transposases of class 11 transposons. ORF2, transcribed in the opposite direction, codes for a protein of 213 amino acids which is highly homologous to DNA invertases and resolvases of class II transposons. Homology of ORF1 and ORF2 and the genetic structure of the element indicate that Tn163 can be classified as a class II transposon. It is the first example of a native transposon in the genus Rhizobium. ORF3, which was found not to be involved in the transposition process, encodes a putative protein (256 amino acids) of unknown function. During transposition Tn163 produced direct repeats of 5 bp, which is typical for transposons of the Tn3 family. However, one out of the ten insertion sites sequenced showed a 6 by duplication of the target DNA; all duplicated sequences were A/T rich. Insertion of Tn163 into the sacB gene revealed two hot spots. Chromosomes of different R. leguminosarum bv. viciae strains were found to be highly refractory to the insertion of Tn163.