Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant de...Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 （named after the Arabidopsis homologous gene AtCAND1）. The defect of visible crown root in the Oscandl mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog ofArabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DRS：：GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscandl. Taken together, these data show that O5CAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice.展开更多
Detection of F. solani f. sp. cucurbitae causal agent of the crown and root rot disease of melon race 1, race 2 is difficult. It is based only on morphological characteristic. In this study, forty isolates identified ...Detection of F. solani f. sp. cucurbitae causal agent of the crown and root rot disease of melon race 1, race 2 is difficult. It is based only on morphological characteristic. In this study, forty isolates identified as Fusarium solani based on morphological characterization, F. solani was one of the most frequently isolated species. Molecular identification of these isolates by PCR technique using species-specific primer, indicated that thirty-two isolates, amplified product 580 bp (race 1) and two isolate amplified product 580 bp (race 2), while six isolates were not amplified with primer of both races. Production of Trichothecenes (T2-toxen, DON.) by Fusarium solani was conducted on isolates confirmed as belonging in the F. solani by PCR. The results indicated that the presence of Tri5, Tri13 genes is coding the ability of synthesis mycotoxin. In vitro, the results indicated that NPs (AgNPs, MgNPs) and chemical (Phylex) possess the antifungal properties against at various level. Treatment with (AgNPs 150 ppm, MgNPs 2%, 3% ppm) and 3% Phylex resulted in maximum inhabitation of F. solani . In vivo, five characters (height plant, hoot ant root fresh and dry weight) were measured based on the greenhouse, field experimental results. Treatment with (AgNPs, MgNPs) and Phylex had higher measured parameters than positive control.展开更多
Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, i...Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.展开更多
The aim of this study is to assess if there is a significant difference between crown to root ratio of male and female permanent teeth in Chinese people in Shanghai.Methods: For this purpose one thousand four hundred ...The aim of this study is to assess if there is a significant difference between crown to root ratio of male and female permanent teeth in Chinese people in Shanghai.Methods: For this purpose one thousand four hundred (700,male and 700,female) extracted teeth were collected between age 25-35 and the crown length (CL) and root length (RL) of permanent teeth were measured by a precise caliper.Statistical analyses were performed with the SPSS 17 software by Student's t-test method.Results: The mean crown length of permanent teeth of male was found to be larger than that of female except for maxillary central incisor and the mean root length of male was found to be comparatively larger than that of female.Conclusion: There was a significant difference in root to crown ratio (RL/CL) between male maxillary teeth and mandibular teeth and female ones.The RL/CL ratio of male tends to be larger than those of female in Shanghai population.展开更多
文摘Crown roots are main components of the fibrous root system and important for crops to anchor and absorb water and nutrition. To understand the molecular mechanisms of crown root formation, we isolated a rice mutant defective in crown root emergence designated as Oscand1 （named after the Arabidopsis homologous gene AtCAND1）. The defect of visible crown root in the Oscandl mutant is the result of cessation of the G2/M cell cycle transition in the crown root meristem. Map-based cloning revealed that OsCAND1 is a homolog ofArabidopsis CAND1. During crown root primordium development, the expression of OsCAND1 is confined to the root cap after the establishment of fundamental organization. The transgenic plants harboring DRS：：GUS showed that auxin signaling in crown root tip is abnormal in the mutant. Exogenous auxin application can partially rescue the defect of crown root development in Oscandl. Taken together, these data show that O5CAND1 is involved in auxin signaling to maintain the G2/M cell cycle transition in crown root meristem and, consequently, the emergence of crown root. Our findings provide new information about the molecular regulation of the emergence of crown root in rice.
文摘Detection of F. solani f. sp. cucurbitae causal agent of the crown and root rot disease of melon race 1, race 2 is difficult. It is based only on morphological characteristic. In this study, forty isolates identified as Fusarium solani based on morphological characterization, F. solani was one of the most frequently isolated species. Molecular identification of these isolates by PCR technique using species-specific primer, indicated that thirty-two isolates, amplified product 580 bp (race 1) and two isolate amplified product 580 bp (race 2), while six isolates were not amplified with primer of both races. Production of Trichothecenes (T2-toxen, DON.) by Fusarium solani was conducted on isolates confirmed as belonging in the F. solani by PCR. The results indicated that the presence of Tri5, Tri13 genes is coding the ability of synthesis mycotoxin. In vitro, the results indicated that NPs (AgNPs, MgNPs) and chemical (Phylex) possess the antifungal properties against at various level. Treatment with (AgNPs 150 ppm, MgNPs 2%, 3% ppm) and 3% Phylex resulted in maximum inhabitation of F. solani . In vivo, five characters (height plant, hoot ant root fresh and dry weight) were measured based on the greenhouse, field experimental results. Treatment with (AgNPs, MgNPs) and Phylex had higher measured parameters than positive control.
文摘Phytophthora root and crown rot was found on the fruit trees in Bulgaria for the first time in the period 1998-1999. Monitoring of the disease spread from 2000 to 2007 points out incidence between 2 and 14 per cent, in some orchards and nurseries in the Southern part of Bulgaria. The following Phytophthora species were identified based on morphological and cultural characteristics, and temperature requirements： Phytophthora cactorum, Phytophthora citrophthora, Phytophthora drechsleri, Phytophthora cryptogea, Phytophthora hybrid specie and Pythium. Prevailing specie was P. cactorum. P. cryptogea and P. cactorum were confirmed by application of molecular methods. Nutritional requirements of P. cactorum and P. citrophthora were studied. Most Nitrogen sources stimulated the mycelial growth of P. cactorum to a higher extend, and reduced the colony size ofP. citrophthora. Different Carbon sources were utilized well by P. cactorum, and only saccharose and maltose had a stimulating effect on the mycelial growth of P. citrophthora. MgSO4.7H20 was the preferred sulfur source for both fungi, as L-cysteine and L-methionine only for P. cactorum. Phytophthora infection leads to physiological changes in the.host plant tissues. The tendency traced out is： about disorders in the amino acid metabolism, increase in the total sugars and slight reduction of the cellulose content. The total nitrogen, phosphorus and potassium content are reduced and the calcium and magnesium are increased. Photosynthesis of inoculated plants was suppressed and transpiration was increased.
文摘The aim of this study is to assess if there is a significant difference between crown to root ratio of male and female permanent teeth in Chinese people in Shanghai.Methods: For this purpose one thousand four hundred (700,male and 700,female) extracted teeth were collected between age 25-35 and the crown length (CL) and root length (RL) of permanent teeth were measured by a precise caliper.Statistical analyses were performed with the SPSS 17 software by Student's t-test method.Results: The mean crown length of permanent teeth of male was found to be larger than that of female except for maxillary central incisor and the mean root length of male was found to be comparatively larger than that of female.Conclusion: There was a significant difference in root to crown ratio (RL/CL) between male maxillary teeth and mandibular teeth and female ones.The RL/CL ratio of male tends to be larger than those of female in Shanghai population.
