The agronomic property of elite cotton hybrid F2 was studied and the results showed that each investigated trait showed consecutive normal distribution except micronaire,so they were typically quantitative characters ...The agronomic property of elite cotton hybrid F2 was studied and the results showed that each investigated trait showed consecutive normal distribution except micronaire,so they were typically quantitative characters controlled by micro-effect polygene.Heterosis analysis indicated that the inbreeding depression of F2 generation was significant,and the heterosis was less than F1 in yield and its component traits,but the yield of F2 generation was prior to the control.Heterosis of most fiber property was very low,some of which were negatively significant.The entire variations indicated that the segregation of fiber property trait was objective and abundant in F2 population.展开更多
One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, litt...One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, little is known with regard to co-occurrence patterns in above-ground and below-ground communities. In this paper, we used a null model to test non-randomness in the structure of the above-ground and below-ground mite communities in farmland of the Sanjiang Plain, Northeast China. Then, we used four tests for non-randomness to recognize species pairs that would be demonstrated as significantly aggregated or segregated co-occurrences of the above-ground and below-ground mite communities. The pattern of the above-ground mite commu- nity was significantly non-random in October, suggesting species segregation and hence interspecific competition. Additionally, species co-occurrence patterns did not differ from randomness in the above-ground mite community in August or in below-ground mite com- munities in August and October. Only one significant species pair was detected in the above-ground mite community in August, while no significant species pairs were recognized in the above-ground mite community in October or in the below-ground mite communities in August and October. The results indicate that non-randomness and significant species pairs may not be the general rule in the above-ground and below-ground mite communities in farmland of the Sanjiang Plain at the fine scale.展开更多
The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different tim...The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC50 of either essential oils or monoterpenoids against the mite was time dependant. The LCso values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus.展开更多
The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practic...The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practices. The values of abundance, species richness, diversity and evenness were significantly larger in OT and ON than in CT, indicating that the abundance and diversity in organic farming fields were greater than those in conventional farming. The community structure of enchytraeid genera was different between OT and ON. Enchytraeus was the most abundant in OT, while Fridericia in ON. The abundance of oribatids in OT was similar to that in ON, while the species richness and diversity in the former were smaller. These results suggested that no-tillage practice under organic management might contribute to the improvement in quality of soil mesofauna.展开更多
基金Supported by the Special Program of National Transgenic Plant Research and Industrialization the Key Sub-program of Cotton Ramie Breeding of Sichuan Province~~
文摘The agronomic property of elite cotton hybrid F2 was studied and the results showed that each investigated trait showed consecutive normal distribution except micronaire,so they were typically quantitative characters controlled by micro-effect polygene.Heterosis analysis indicated that the inbreeding depression of F2 generation was significant,and the heterosis was less than F1 in yield and its component traits,but the yield of F2 generation was prior to the control.Heterosis of most fiber property was very low,some of which were negatively significant.The entire variations indicated that the segregation of fiber property trait was objective and abundant in F2 population.
基金Under the auspices of National Natural Science Foundation of China(No.41101049,40601047,41371072,31101617,41171047)China Postdoctoral Science Foundation(No.2012M511361)+2 种基金Excellent Youth Scholars of Northeast Institute of Geography and Agroecology,Chinese Academy of Sciences(No.DLSYQ2012004)Fund for Distinguished Young Scholar of Harbin Normal University(No.KGB201204)Scientific Innovation Project for Doctoral Candidate of Harbin Normal University(No.HSDBSCX2012-07)
文摘One of the fundamental questions in community ecology is whether communities are random or formed by deterministic mechanisms. Although many efforts have been made to verify non-randomness in community structure, little is known with regard to co-occurrence patterns in above-ground and below-ground communities. In this paper, we used a null model to test non-randomness in the structure of the above-ground and below-ground mite communities in farmland of the Sanjiang Plain, Northeast China. Then, we used four tests for non-randomness to recognize species pairs that would be demonstrated as significantly aggregated or segregated co-occurrences of the above-ground and below-ground mite communities. The pattern of the above-ground mite commu- nity was significantly non-random in October, suggesting species segregation and hence interspecific competition. Additionally, species co-occurrence patterns did not differ from randomness in the above-ground mite community in August or in below-ground mite com- munities in August and October. Only one significant species pair was detected in the above-ground mite community in August, while no significant species pairs were recognized in the above-ground mite community in October or in the below-ground mite communities in August and October. The results indicate that non-randomness and significant species pairs may not be the general rule in the above-ground and below-ground mite communities in farmland of the Sanjiang Plain at the fine scale.
文摘The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC50 of either essential oils or monoterpenoids against the mite was time dependant. The LCso values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus.
文摘The major soil animal groups, enchytraeid worms and oribatid mites, were compared in the abundance and diversity between conventional fields (CT) and organic farming fields with tillage (OT) or no-tillage (ON) practices. The values of abundance, species richness, diversity and evenness were significantly larger in OT and ON than in CT, indicating that the abundance and diversity in organic farming fields were greater than those in conventional farming. The community structure of enchytraeid genera was different between OT and ON. Enchytraeus was the most abundant in OT, while Fridericia in ON. The abundance of oribatids in OT was similar to that in ON, while the species richness and diversity in the former were smaller. These results suggested that no-tillage practice under organic management might contribute to the improvement in quality of soil mesofauna.
