After examining ear-colonizing pest resistance, 20 maize lines from the USDA- ARS Germplasm Enhancement of Maize （GEM） Program were evaluated for whorl-feeding fall armyworm （FAW） （Spodopterafrugiperda） resistan...After examining ear-colonizing pest resistance, 20 maize lines from the USDA- ARS Germplasm Enhancement of Maize （GEM） Program were evaluated for whorl-feeding fall armyworm （FAW） （Spodopterafrugiperda） resistance using 4 maize inbred lines as the resistant and susceptible controls. Both FAW injury ratings at 7- and 14-d after infestation, and predator abundance and diversity at whorl stage （V6-V8） were recorded in 2009 and 2010. The survey of the diversity and abundance of predators in each experimental plot were conducted 7 d after the FAW infestation. Of the 20 germplasm lines examined, 3 of them （i.e., entries 9, 15, and 19 that were derived from tropical maize germplasm lines were originated from Uruguay, Cuba, and Thailand, respectively） were identified as the best FAW-resistant germplasm lines using the leaf injury ratings and predator survey data. In addition, the abundance and diversity of the predators were greater in 2010 than in 2009, which might have caused the low level of the FAW injury ratings on all lines examined in 2010. The 2-year data showed that the FAW injury ratings were negatively correlated to the predator abundance and diversity, which is also influence by genotype × environment interactions. The findings suggested that tropical germplasm is an important source of native resistance to the FAW and the corn earworm. At the same time, the maize genotype x environment interaction （e.g., predator attractiveness, and varying weather conditions） should be included in the multiple-year evaluations of insect and disease resistance of maize germplasm lines under field conditions.展开更多
Abundance distribution models and diversity-area relationships are tools of biological diversity analysis that have been used by ecologists for decades. In a case study by Ibez et al., these techniques are considered ...Abundance distribution models and diversity-area relationships are tools of biological diversity analysis that have been used by ecologists for decades. In a case study by Ibez et al., these techniques are considered in a mor e general setting, and have been applied to explore notions such as pedodiversity (as an example of geodiversity in a broad sense, including also geomorphic diversity), in order to detect the differences and similarities between both natural resources, biological and non-biological.The discussion has mainly been conducted through the study of the Aegean Islands by the Spanish research team. Standard statistical techniques have been applied to analyze how the pedotaxa-abundance distribution conforms to the abundance distribution models and how pedorichness-area data fit to the diversity-area models.No statistically significant difference has been observed between the abundance distribution models and the diversity-area relationships followed by biodiversity and pedodiversity data in similar situations. Thus, the studied results may suggest that some assumptions underlying biodiversity analysis ought to be carefully re-examined.Since results in ecological literature are usually interpreted in biological terms, the analysis by Ibáez et al. may be relevant to offer some suggestions to the following questions: What are the reasons for the similarities obtained between biotic and soil resources? Should the ecological theory modify some of its constructs once the said similarities have been proven? and what are its implications for environmental management and assessment?展开更多
文摘After examining ear-colonizing pest resistance, 20 maize lines from the USDA- ARS Germplasm Enhancement of Maize （GEM） Program were evaluated for whorl-feeding fall armyworm （FAW） （Spodopterafrugiperda） resistance using 4 maize inbred lines as the resistant and susceptible controls. Both FAW injury ratings at 7- and 14-d after infestation, and predator abundance and diversity at whorl stage （V6-V8） were recorded in 2009 and 2010. The survey of the diversity and abundance of predators in each experimental plot were conducted 7 d after the FAW infestation. Of the 20 germplasm lines examined, 3 of them （i.e., entries 9, 15, and 19 that were derived from tropical maize germplasm lines were originated from Uruguay, Cuba, and Thailand, respectively） were identified as the best FAW-resistant germplasm lines using the leaf injury ratings and predator survey data. In addition, the abundance and diversity of the predators were greater in 2010 than in 2009, which might have caused the low level of the FAW injury ratings on all lines examined in 2010. The 2-year data showed that the FAW injury ratings were negatively correlated to the predator abundance and diversity, which is also influence by genotype × environment interactions. The findings suggested that tropical germplasm is an important source of native resistance to the FAW and the corn earworm. At the same time, the maize genotype x environment interaction （e.g., predator attractiveness, and varying weather conditions） should be included in the multiple-year evaluations of insect and disease resistance of maize germplasm lines under field conditions.
文摘Abundance distribution models and diversity-area relationships are tools of biological diversity analysis that have been used by ecologists for decades. In a case study by Ibez et al., these techniques are considered in a mor e general setting, and have been applied to explore notions such as pedodiversity (as an example of geodiversity in a broad sense, including also geomorphic diversity), in order to detect the differences and similarities between both natural resources, biological and non-biological.The discussion has mainly been conducted through the study of the Aegean Islands by the Spanish research team. Standard statistical techniques have been applied to analyze how the pedotaxa-abundance distribution conforms to the abundance distribution models and how pedorichness-area data fit to the diversity-area models.No statistically significant difference has been observed between the abundance distribution models and the diversity-area relationships followed by biodiversity and pedodiversity data in similar situations. Thus, the studied results may suggest that some assumptions underlying biodiversity analysis ought to be carefully re-examined.Since results in ecological literature are usually interpreted in biological terms, the analysis by Ibáez et al. may be relevant to offer some suggestions to the following questions: What are the reasons for the similarities obtained between biotic and soil resources? Should the ecological theory modify some of its constructs once the said similarities have been proven? and what are its implications for environmental management and assessment?
