贵州野生大麦麦芽品质性状的SSR标记分析

采用6对啤酒大麦的麦芽浸提和糖化力紧密连锁引物对103份采自贵州的野生大麦材料进行SSR标记。结果表明,贵州野生大麦麦芽品质性状存在丰富的变异,6对SSR引物共检测出38个等位变异,每个位点平均6.33个等位变异,其中GMS001位点对贵州野生大麦基因组DNA变异检测最有效。UPGMA聚类图显示,该6对与麦芽品质紧密连锁的SSR引物对区分野生大麦在贵州不同的资源产地和棱性是有效的,表现为遵义地区野生大麦遗传多样性丰富,而来自贵州凯里地区的野生大麦资源遗传多样性狭窄。麦芽品质性状标记结果表明贵州野生六棱大麦较四棱大麦的遗传差异更显著,表明进行贵州啤酒大麦人工育种的亲本应在亲缘关系较远的六棱大麦之间选择。     

Microsatellite loci from Taxus chinensis var. mairei (Taxaceae), an endangered and economically important tree species in China

Taxus chinensis var.mairei is an endangered and economically important tree species in China.Four polymorphic microsatellite markers were developed and characterized using the fast isolation by amplified fragment length polymorphism (AFLP) of sequences containing repeats (FIASCO) protocol.Polymorphism of each locus was quantified for five natural populations from Hubei Province,China.The number of alleles per locus varied from 6 to 24.The ranges of observed and expected heterozygosity were 0.493-1.000 and 0.440-0.845,respectively.These are the first microsatellites reported for the family of Taxaceae and will be helpful for the ongoing population and conservation genetics research of Taxus chinensis var.mairei.     

陇东海棠(Malus kansuensis)一新异名

将伏牛海棠Malus komarovii Rehd.var.funiushanensis S.Y.Wang作为异名归并入陇东海棠Malus kansuensis(Batal.)Schneid.。     

单叶黄荆的分类学修订

根据对单叶黄荆(Vitex simplicifolia)模式标本的研究,结合在其模式产地的野外调查,发现单叶黄荆与黄荆(V.negundo)并无本质区别,不宜作为独立的种,但其叶片为单叶而且比较稳定,将其降级并组合为黄荆的变种。     

Glycan-binding profile of a D-galactose binding lectin purified from the annelid, Perinereis nuntia ver. vallata

A lectin recognizing D-galactose was purified from the pacific annelid Perinereis nuntia ver. vallata (Polychaeta) by affinity chromatography. Hemagglutinating activity, with a very low titer suggesting the presence of lectin appeared in the supernatant from the homogenization of body with Tris-buffered saline. However, dialyzed supernatant from the precipitate homogenized by galactose in the buffer revealed strong hemagglutinating activity against human erythrocytes. The crude supernatant was applied onto lactosyl–agarose column, and only the supernatant eluted from precipitate with galactose was obtained a galactose-binding lectin with 32 kDa polypeptide was obtained from the supernatant of the precipitate, extracted in presence of galactose. It suggests that the lectin tightly binds with glycoconjugate as endogenous ligand(s) in the tissue. Hemagglutinating activity against trypsinized and glutaraldehyde-fixed human erythrocytes was specifically inhibited by D-galactose, N-acetyl-D-galactosamine, lactose, melibiose, and asialofetuin. Glycan-binding profile of the lectin analyzed by frontal affinity chromatography shows that the lectin recognizes branched complex type N-linked oligosaccharides and both type 1 (Galβ1-3GlcNAc) and type 2 (Galβ1-4GlcNAc) lactosamine. The surface plasmon resonance study of the lectin against asialofetuin showed the k_ass and k_diss values are 5.14 × 10⁴ M^− 1 s^− 1 and 2.9 × 10⁻³ s^− 1, respectively. The partial primary structure of the lectin reveals 182 amino acids with novel sequence.     

Isolation of polymorphic microsatellite loci in Livistona chinensis (Jacq.) R.Br. ex Mart. var. boninensis Becc., an endemic palm species of the oceanic Bonin Islands, Japan

A set of microsatellites markers were developed for Livistona chinensis var. boninensis, an endemic palm tree of the Bonin Islands. We obtained 123 sequences containing unique microsatellites from an enriched library. Twelve loci were screened for their feasibility using 32 trees. They showed polymorphisms with two to nine alleles per locus. No significant deviation from Hardy–Weinberg equilibrium was observed for 11 loci. No genotypic disequilibrium was detected between any two of the loci. Total exclusionary powers for the first and the second parents were 0.978774 and 0.998987, respectively. These markers will allow us to investigate the gene flow within/among populations of the species.     

Predating strategy of rodents on acorns of Quercusaliena var. acuteserrata under different predating risks and fate of acorns

The effects of rodents on forest regeneration have been highlighted in many ecological studies. In 2002 and 2003, the acorns of Quercus aliena var. acuteserrata were subjected to 12 different treatments. The daily dynamics and the amount of acorns that were finally left intact, predated in situ, or removed off were examined and documented. The ratios of acorns that were infested by bugs before and after predation by rodents were carefully documented. It was found that: (1) the ratios of acorns infested by bugs before and after predation by rodents showed significant difference (P > 0.05), suggesting that rodents would not prey on acorns during the predating process if acorns had been already infested by bugs. (2) When compared with the controls, the fate of acorns could be roughly classified into four types: acorns that were simply buried or placed on black paper showed no significant differences with the controls in their response to rodents, suggesting that rodents have no sensitivity to the little change of odor resulting from burying and may be more adapted to black background. Acorns attached with strings, dyed with black ink, cut into halves, or placed on white/green/red paper were predated in situ with much lower predation rates and lasted the same duration. Compared with the controls, the acorns were removed away by rodents with the same first day rate and the removal lasted longer. The final removal rate of the acorns by rodents was increased, whereas that of predation in situ was decreased, and none were left in the spot. This may suggest that rodents in this case increased their predation risk expectation and adopted a strategy of “less predation proportion in situ”. Acorns that were burnt were not predated in situ as well as removed in the first day, but the rates were raised to the maximum in the forth and fifth day and then declined to zero. Consequently, the final ratios of predation in situ and removal considerably decreased with many acorns, nearly 50%, being left intact. It can be hypothesized that the rodents responded to the change in odor of acorns by using the strategies of “less predation proportion in situ” and “less predating activities”, thereby resulting in larger number of acorns remained intact. Acorns that were enwrapped were barely predated in situ, removed in the first day with a normal predation rate, which declined to nearly zero in the second day and then increased till it declined again from the fourth day to the final day. The final rate of predation in situ was lower than 5% without acorns remained intact, and the rate of removal of acorns showed a considerable relative increase. This suggests that when there was a change in both odor and status of acorns, rodents also adopted the “spying” and “less predation proportion in situ” strategy, Because the predation risk is critical, the sense of sight would play an important role in rodent's living. (3) Definite amounts of acorns were predated in situ, discarded, removed away, predated ex situ, lost and hoarded separately.     

The effects of salinity and osmotic stress on barley germination rate: sodium as an osmotic regulator

Background and Aims

Seed germination is negatively affected by salinity, which is thought to be due to both osmotic and ion-toxicity effects. We hypothesize that salt is absorbed by seeds, allowing them to generate additional osmotic potential, and to germinate in conditions under which they would otherwise not be able to germinate.

Methods

Seeds of barley, Hordeum vulgare, were germinated in the presence of either pure water or one of five iso-osmotic solutions of polyethylene-glycol (PEG) or NaCl at 5, 12, 20 or 27 °C. Germination time courses were recorded and germination indices were calculated. Dry mass, water content and sodium concentration of germinating and non-germinating seeds in the NaCl treatments at 12 °C were measured. Fifty supplemental seeds were used to evaluate the changes in seed properties with time.

Key Results

Seeds incubated in saline conditions were able to germinate at lower osmotic potentials than those incubated in iso-osmotic PEG solutions and generally germinated faster. A positive correlation existed between external salinity and seed salt content in the saline-incubated seeds. Water content and sodium concentration increased with time for seeds incubated in NaCl. At higher temperatures, germination percentage and dry mass decreased whereas germination index and sodium concentration increased.

Conclusions

The results suggest that barley seeds can take up sodium, allowing them to generate additional osmotic potential, absorb more water and germinate more rapidly in environments of lower water potential. This may have ecological implications, allowing halophytic species and varieties to out-compete glycophytes in saline soils.     

思茅松微红梢斑螟生物学和生态学特性研究

思茅松微红梢斑螟Dioryctria rubella Hampson在云南省普洱市1年发生3代,世代重叠现象严重。幼虫具有转梢、转枝、转株为害习性,这与气候因素和寄主思茅松的生长状态密切相关。雨季幼虫以转株危害为主,危害率为35%～40%;旱季幼虫以转梢危害为主,危害率为90%～100%。第3代微红梢斑螟发生严重,造成的损失最大。这为综合控制微红梢斑螟对思茅松的危害提供重要的理论基础。