杂交水稻“多系育种”改良效果及应用评价

通过４×６不完全双列杂交和多恢系列恢复系的稻瘟病接种鉴定以及多系组合的比较试验并引用省区试结果，分析了通过“多系育种”育成的恢复系的配合力和抗稻瘟病力以及所配组合的丰产性、抗性和稻米品质。结果表明，“多系育种”育成的恢复系在配合力及抗稻瘟病上超过了公共轮回亲本明恢６３，所配多系杂交稻组合大部份在产量、抗稻瘟病以及稻米品质上超过了汕优６３。多系组合在生产上大面积种植应用应注意不同的多系组合应因种栽培。

A Molecular Phylogeny of Macaca Based on Mitochondrial Control Region Sequences

Nucleotide sequences of segments of the mitochondrial control regions were analyzed to infer the phylogenetic relationships among 7 macaques.High nucleotide diversity in Macaca assamensis and relatively low diversity in M.thibetana were found.Based on the ML tree from control regions,species in our study can roughly be sorted into three species groups except for the phylogenetic position of M.fascicularis,i.e.,silenus group,including M.leonina;sinica group,including M.arctoides,M.assamensis,and M.thibetana;and fascicularis group,including M.mulatta and M.cyclopis.A discrepancy between earlier studies (Fooden & Lanyon,1989;Tosi et al,2003a;Deinard & Smith,2001;Evans et al,1999;Hayasaka et al,1996;Morales & Melnick,1998),our result supported the hypothesis that M.fascicularis diverged earlier than M.leonina.Mitochondrial paraphyly in eastern M.mulatta (with respect to M.cyclopis) and eastern M.assamensis (with respect to M.thibetana) were clearly observed in our study.In accordance with the results of Y chromosome,allozyme,nuclear genes and some morphological data (Delson,1980;Fooden & Lanyon,1989;Fooden,1990;Tosi et al,2000,2003a,b;Deinard & Smith,2001),our study on control region sequences supported M.arctoides to be classified into the sinica group.However,this result disagreed with the previous mtDNA studies (Hayasaka et al,1996;Morales & Melnick,1998;Tosi et al,2003a).

The Various Description of Biodiversity in Compulsory Education Textbooks

We intend to establish how species diversity is dealt with, within the study of the ecosystem, in books for the 4th year of Compulsory Secondary Education, ESO （15-16 year-old students）. The analysis was carried out using a key issues dossier based on school science, which not only provides a description of reality, but also introduces a theoretical explanatory framework. Regarding species diversity, we focused on the descriptive approach, considering the link between diversity and trophic relationships, ecological succession and ecosystem stability through change, consequences for biodiversity of human activities and mechanisms to face such consequences; and on the explanatory perspective, which provides an interpretative answer for all the aspects previously mentioned. The findings drawn from textbooks show that biodiversity is linked both to the study of the ecosystem and to the impact of human societies on its maintenance. However, such study is particularly focused on the descriptive, rather than on the explanatory level. So, teachers should improve the study of biodiversity foresting a balance between descriptive and explanatory level.

Species turnover drives grassland community to phylogenetic clustering over long-term grazing disturbance

Aims Grazing exerts profound effects on grassland ecosystem service and functions by regulating species composition and diversity,and structuring community assembly worldwide.However,adaptions of phylogenetic diversity and phylogenetic community structure to long-term grazing disturbance remain poorly studied,especially for ecosystems distributed in extreme environments.Methods Here,we conducted an experiment with multigrazing intensities to explore the impacts of grazing disturbance on plant phylogenetic diversity and community structure in an alpine grassland of the Tibetan Plateau.Important Findings Grazing disturbance enriched plant species richness(SR),and stimulated species turnover from regional species pool,consequently changing community species composition.Under low intensities,grazing exerted no obvious effects on phylogenetic diversity and community structure,whereas communities changed from overdispersion to clustering under high grazing intensity.High grazing intensity resulted in stronger environmental filtering,which consequently selected those species with high resilience to grazing disturbance.The observed clustering structure was associated with the colonizing species which were closely related to resident species,and locally extinct species,and distantly related to residents.At the plant functional trait level,high grazing intensity increased species colonization largely by altering the effect of root depth on species colonization compared to light grazing.Our results highlight that solely utilization of SR and diversity cannot fully represent grassland communities responses to grazing.The effects of species turnover on community phylogenetic diversity and structure are entailed to be explored in the future grazing studies.