Summary Pollen from the inbred maize line HMv 1645 was used to study the effect of pollen treatments (drying and deep-freezing) on the phenotypic performance of the next generation. Fresh and artificially dried pollen samples with different water contents (56%, 18%, 13% and 10%) were used for sib pollinations immediately after collection or drying. Samples containing low amounts of water were then stored in liquid nitrogen for 7 days. Fertilization ability of the samples with 13% water was the highest after storage. Plant characteristics of the next generation originated from the seeds set by differently treated (fresh, dried to 13% water and deep-frozen) pollen were examined and statistically analysed. Pollen treatments due to the pollen storage procedure did not cause detectable changes in quantitative characters of the next generation. 相似文献
Post-adoption studies are relatively uncommon in the agroforestry literature. Thus little is known about progress and permanence following adoption. To better understand the relationship between agroforestry implementation and community development, seventy-seven practitioners in Cameroon with three or more years of experience were surveyed about the relationships between agroforestry and community development. Hypotheses were that they have observed differences in the association between agroforestry and community capitals. They were also surveyed about their satisfaction with agroforestry. Hypotheses were that satisfaction is high and negatively skewed when compared to community capitals measurements. Game play was used to collect responses. Friedman’s two-way non-parametric statistic was used to test for inter-item differences within the community capitals and satisfaction response sets. Shapiro–Wilk statistic was used to test for normality in both response sets and a bootstrap procedure and t-tests were used to test for differences in data skewness and kurtosis. Natural capital scored highest but did not differ significantly from built, human, and social capitals. Financial capital was significantly lower than natural capital, but not built, human, or social capitals. Political and cultural capitals were significantly lower compared to all others. Satisfaction was significantly higher when compared to community capitals, but the data were also negatively skewed suggesting capitals are a more representative and useful metric for researchers and technical assistance professionals focused on long-term practitioner support. 相似文献
The effect of the parental genotypes and colchicine treatment on the androgenic response of wheat (Triticum aestivum L.) F1 hybrids was studied. For this, anthers from three F1 hybrids and their parents were cultured on W14 initiation medium and W14 supplemented with 0.03% colchicine. The number of responding anthers, microspore‐derived structures/100 anthers, green plants/embryos cultured, green plants/100 anthers and albino plants/100 anthers were recorded. It was observed that embryo formation and plant regeneration ability were genetically controlled and genotype dependent. In both treatments the variety Kavkaz had a significantly higher percentage of responding anthers, microspore‐derived structures and green plants/100 anthers than the other genotypes. On the other hand, the variety Myconos also demonstrated high microspore‐derived structure production and green plant regeneration when treated with colchicine. The good response observed in these two varieties indicates the importance of colchicine treatment only for certain genotypes. Green plant production capacity of the hybrids was intermediate to that of the parental varieties. As one parent with a high or even an intermediate response to anther culture could lead to the production of sufficient (for breeding purposes) green plants from the F1 hybrids, it was concluded that screening the inbred lines for the response to anther culture with and without colchicine treatment could contribute to utilization of breeding material with a low response to anther culture via the proper hybrid combinations. 相似文献
Journal of Soils and Sediments - In urban areas, soil functions are deeply impacted by all human activities, e.g., water infiltration, carbon storage, and chemical substances degradation potential.... 相似文献
Reliable data on the contribution of forests to the livelihoods of households in the Congo Basin are not always readily available to governments and decision-makers. This paper assesses the value of forest resources on livelihoods in Cameroon, Republic of Congo, Gabon, Central Africa Republic and the Democratic Republic of Congo. Data were collected using the Forest Poverty Linkages Toolkit, between 2012 and 2014 on stratified samples of 616 Bantu and indigenous people’s households in 15 villages. The study reveals that forest resources account for 48% to 63% of the total revenue of rural households. In Bantu households, estimates of the gross income from the forest per capita/day range from $US 0.18 to $US 1.3. This value is about double that received by indigenous people except in Congo. Non-cash income is about twice as high as cash income. On average, cash income reaches only about 23% of the World Bank $1.25 a day income level for chronic poverty. However, non-cash income - about twice as high as cash income – mitigates these profound poverty levels to some extent. The paper concludes by considering the importance of the findings for policy-making in Central Africa and the Congo Basin, and more widely. It is suggested that much more data of this kind is need to shape appropriate approaches to sustainable forest management, with a better understanding of the economic security and the livelihood resilience of the chronic poor increasingly kept in mind. 相似文献
Red rot caused by Colletotrichum falcatum is one of the most devastating fungal diseases of sugarcane in many tropical countries. In this study, the efficacy of various resistance-inducing agents was evaluated against red rot at two growth phases of sugarcane, i.e., the germination and grand growth phases, for four consecutive cropping seasons (2011–12 to 2014–15) under field conditions. Inducer candidates of both synthetic origin (benzothiadiazole [BTH], salicylic acid [SA], potassium silicate [PSi]) and biotic origin (Colletotrichum falcatum [Cf] elicitor and Reynoutria sachalinensis extract) were evaluated for their efficacy on a red rot susceptible sugarcane cultivar CoC 671. Inducer concentrations that showed significant reduction of red rot lesion length in leaf bioassays without exhibiting direct antifungal activity were used in the field trials. Overall, results of the four field trials indicated that application of BTH (125 μM) and Cf elicitor (60 μg glucose equivalent/ml) were most efficient in reducing disease incidence during the germination and establishment phases against soil-borne inoculum and suppressed disease severity in pathogen challenged cane stalks during the grand growth phase. In addition, other treatments also had significant effects on germination and stalk disease severity. Quantification of C. falcatum biomass in resistance inducer-treated canes by quantitative PCR (qPCR) substantiated the disease suppressive effect of BTH and Cf elicitor. Whereas all resistance inducers significantly increased the cane weight, only BTH and PSi significantly increased the juice quantity. Other juice quality parameters were generally not affected by the inducers. 相似文献
Paracetamol, the most widely and globally used analgesic and antipyretic, is easily accumulated in aquatic environments. In the present study, the biodegradation of paracetamol in different media (one for general growth, one specific for sulfate reducing bacteria, a mineral salts medium and municipal wastewater) inoculated with two types of sludge (from anaerobic lagoon and from oxidation ditch) under different oxygenic conditions (anoxic; moderate oxygenation in open flasks and high oxygenation by aeration) was investigated. In addition, bacteria with relative abundances increasing simultaneously with paracetamol degradation, when this drug was the only carbon source, thus with a putative role in its degradation, were identified using 16S rRNA gene sequences. The results show that aerobic microorganisms had a major role in the degradation of paracetamol, with 50 mg/L totally removed from municipal wastewater after 2 days incubation with aeration, and that the metabolites 4-aminophenol and hydroquinone plus one compound not identified in this work were produced in the process. The identification of bacteria with a role in the degradation of paracetamol revealed a strain from genus Pseudomonas with the highest final relative abundance of 21.2%, confirming previous works reporting strains of this genus as paracetamol decomposers. Besides, genera Flavobacterium, Dokdonella and Methylophilus were also in evidence, with initial relative abundances of 1.66%, 1.48 and 0.00% (not detected) in the inoculum and 6.91%, 3.80 and 3.83% after incubation, respectively. Therefore, a putative role of these genera in paracetamol biodegradation is suggested for the first time.
The virus causing horsegram (Macrotyloma uniflorum) yellow mosaic disease has been shown to be a typical Old World bipartite begomovirus. The viral origin of the disease has
been established through agroinoculation of horsegram using partial tandem repeat clones of both DNA-A and DNA-B. The DNA-A
genome shows less than 89% identity with the corresponding sequences of all the begomoviruses in the databases earlier to
this sequence submission (AJ627904). Therefore Horsegram yellow mosaic virus (HgYMV-[IN:Coi]) can be considered to be a new species of the genus Begomovirus (family Geminiviridae). Phylogenetic analysis shows that this virus is part of the cluster of mungbean yellow mosaic viruses of legumes from South
and South East Asia. 相似文献
In contrast to conventional inbreeding that takes up to seven generations to develop inbred lines, the doubled haploid (DH) technology allows production of inbred lines in two generations. The objectives of the present study were to: (a) evaluate testcross performance of 45 doubled haploid lines under drought stress and non-stress conditions (b) estimate heritabilities for grain yield and other traits and (c) to assess the genetic distance and relationship among the DH lines using 163,080 SNPs generated using genotyping-by-sequencing (GBS). The 45 hybrid and five checks were evaluated using a 10 × 5 alpha lattice in six drought stress and nine well-watered environments in Kenya, Uganda, and Tanzania. Differences in trait means between the drought stress and well-watered conditions were significant for all measured traits except for anthesis date. Genetic variances for grain yield, grain moisture, plant height and ear height were high under well-watered environments while genetic variance for anthesis date, root lodging and stalk lodging were high under drought stress environments. Combined analyses across drought stress and well-watered environments showed that ten top hybrids produced 1.6–2.2 t/ha grain yield under well-watered condition and 1–1.4 t/ha under drought stress condition higher than the mean of the commercial checks. Genetic distance between pairwise comparisons of the 38 of the 45 DH lines ranged from 0.07 to 0.48, and the overall average distance was 0.36. Both cluster and principal coordinate analysis using the genetic distance matrix calculated from 163,080 SNPs showed two major groups and the patterns of group was in agreement with their pedigree. Thirteen (13) of the best hybrids are currently in National Performance Trials testing, an important step towards commercialization in Kenya, Tanzania and Uganda. 相似文献
