Discoloration induced by Raffaelea quercivora isolates in Quercus serrata logs and its relation to phylogeny: a comparison among isolates with and without the Japanese oak wilt incidence including outside of Japan     

Dai Kusumoto  Hayato Masuya  Toshihide Hirao  Hideaki Goto  Keiko Hamaguchi  Wen-I Chou  Wiwat Suasa-ard  Sawai Buranapanichpan  Sopon Uraichuen  Oraphan Kern-asa  Sunisa Sanguansub  Aumporn Panmongkol  Thu Pham Quang  Sih Kahono  Heddy Julistiono  Naoto Kamata 《Journal of Forest Research》2014,19(4):404-410

Japanese oak wilt (JOW) has been prevalent in Japan since the late 1980s. Infections of the fungus, Raffaelea quercivora Kubono et Shin. Ito, which is transmitted by an ambrosia beetle [Platypus quercivorus (Murayama)], can cause JOW. Although R. quercivora, P. quercivorus, and oak trees are distributed in other Asia–Pacific countries, the incidence of JOW has not been reported outside Japan. In this study, we collected R. quercivora isolates from 5 Asian countries, including Japan, and compared their ability to induce sapwood discoloration by inoculating Q. serrata logs. The tangential widths of the discoloration in sapwoods inoculated with non-Japanese isolates were equivalent to or greater than those of the 2 Japanese isolates. This indicates that a lack of JOW incidence outside Japan is not because of the lowered ability of R. quercivora to spread discoloration compared with the Japanese isolates. Statistical analyses of the relationship between discoloration and phylogeny based on DNA sequences of actin and chitin synthase showed that the discoloration width was independent of phylogenetic relatedness among the isolates. To discuss why the occurrence of JOW has not been reported outside Japan, further studies (e.g., on host susceptibility and P. quercivorus aggression) throughout Asia are needed.  相似文献   

Growth of uniformly oriented silica MFI and BEA zeolite films on substrates     

Pham TC  Kim HS  Yoon KB 《Science (New York, N.Y.)》2011,334(6062):1533-1538

Applications of zeolite films benefit from alignment of the integrated channels, but methods for film growth have nearly always introduced orientational randomization in the direction normal to the substrate. We now report facile methods to grow silicalite-1 films and pure silica beta zeolite films on substrates with straight or sinusoidal channels positioned uniformly upright at a thickness of up to 8 micrometers. Precise gel compositions and processing temperatures are critical to promote secondary growth on pre-formed oriented crystal monolayers while suppressing self-crystallization in the bulk medium. Preliminary results highlight the potential of these uniformly oriented films in the nonlinear optical response and separation of xylene isomers.  相似文献   

Rural income generation through improving crop-based pig production systems in Vietnam: Diagnostics,interventions, and dissemination   总被引：1，自引：0，他引：1  

Dai?PetersEmail author  Nguyen?Thi?Tinh  Mai?Thach?Hoan  Nguyen?The?Yen  Pham?Ngoc?Thach  Keith?Fuglie 《Agriculture and Human Values》2005,22(1):73-85

Sweetpotato-pig production is an important system that generates income, utilizes unmarketable crops, and provides manure for soil fertility maintenance. This system is widely practiced from Asia to Africa, with many local variations. Within this system, pigs are generally fed a low nutrient-dense diet, yielding low growth rates and low economic efficiency. Our project in Vietnam went through a process of situation analysis, participatory technology development (PTD), and scaling up over a seven-year period to improve sweetpotato-pig production and to disseminate developed technologies. The situation analysis included a series of pig production assessments in several provinces in northern and southern Vietnam, and pig supply-market chain identification was conducted in 13 provinces. The analysis of these studies informed the project of the following: (1) appropriate locations for our activities; (2) seasonal available feedstuff and farmers feeding practices; (3) market fluctuation and requirements; and (4) feeding and management improvement needs based on which the subsequent phase of PTD was designed. The PTD involved a limited number of farmers participating in sweetpotato varietal selection, sweetpotato root and vine silage processing, seasonal feeding combination, and pig feeding with balanced crop-feed diet and silage. Six years of multi-location and multi-season sweetpotato selection resulted in a few promising varieties that yielded up to 75% more dry matter and have since been formally released. The most significant results of silage processing and feeding trials include improved growth, higher feeding efficiency, increased year-round local feedstuff, and considerable labor reduction from eliminated cooking and vine cutting. Once these technologies were developed, a farmer-to-farmer training model was designed for scaling up the adoption and impact. Farmer trainers from seven communes in seven provinces received training in these technologies. In turn, they undertook the responsibility of training other farmers on sweetpotato selection, processing, and feeding. An impact study was also administered to monitor and evaluate (M&E) the dissemination process and to document the impact of the new technologies and farmer-to-farmer training model on pig growth and farmer income generation. The results showed that both participating and non-participating farmers have taken up the technologies, although the former demonstrates higher rates of adoption than the latter. The participants also generated more income and saved more labor from the adoption of the technologies. While the scaling up and M&E activities are on-going, the project has since broadened from a sweetpotato-pig system perspective to a pig-cropfeed system perspective based on farmers needs. It has included other crop feeds such as cassava and peanut stems in the research portfolio. New technologies based on on-going PTD will continuously be incorporated into the future training curriculum.Dai Peters is currently a senior scientist with the International Center for Tropical Agriculture (CIAT) based in Hanoi, Vietnam. This publication is based on research conducted while she was a research scientist with the International Potato Center (CIP). She holds a PhD from North Carolina State University. Her research interests include on-farm participatory research methodologies, agroenterprise development, and sweetpotato-pig farming systems in Vietnam and Papua, Indonesia. Her recent publications include a manual on crop-based pig feed systems, post-harvest fermentation of sweetpotato roots and vines, and agroenterprise development.Nguyen Thi Tinh is currently a coordinator of the sweetpotato-pig improvement project at the International Potato Center in Vietnam. Ms. Tinh holds a Masters degree in animal nutrition from Wageningen University, Netherlands. She participated in the project on pig feeding trials for five years.Mai Thach Hoanh is a sweetpotato breeder with the Root Crop Research Center of Vietnam Agricultural Science Institute (VASI). He holds a PhD in sweetpotato breeding from the same institute. He participated in the project for seven years on sweetpotato selection. Nguyen The Yen is a crop scientist in the Food Crop Research Institute of Vietnam. He holds a PhD in sweetpotato breeding from VASI. He participated in the project for five years on sweetpotato selection.Pham Ngoc Thach is a lecturer with the Hanoi Agricultural University. He holds a PhD in veterinarian science from the same university. He participated in the project for five years in controlling pig diseases during the feeding trials.Keith Fuglie is a regional coordinator and research scientist in the International Potato Center based at Bogor, Indonesia. He holds a PhD in agriculture economics from the University of Wisconsin. He designed the impact study for the project.  相似文献   

Requirement for the SLP-76 adaptor GADS in T cell development     

Yoder J  Pham C  Iizuka YM  Kanagawa O  Liu SK  McGlade J  Cheng AM 《Science (New York, N.Y.)》2001,291(5510):1987-1991

GADS is an adaptor protein implicated in CD3 signaling because of its ability to link SLP-76 to LAT. A GADS-deficient mouse was generated by gene targeting, and the function of GADS in T cell development and activation was examined. GADS- CD4-CD8- thymocytes exhibited a severe block in proliferation but still differentiated into mature T cells. GADS- thymocytes failed to respond to CD3 cross-linking in vivo and were impaired in positive and negative selection. Immunoprecipitation experiments revealed that the association between SLP-76 and LAT was uncoupled in GADS- thymocytes. These observations indicate that GADS is a critical adaptor for CD3 signaling.  相似文献   

越南马铃薯晚疫病的研究概况     

PhamXuanTung 《河北农业大学学报》2001,24(2):16-19,31

晚疫病是越南马铃薯上最重要的病害。各马铃薯产区均有发生。在江河三角洲地区晚疫病的发生通常比较晚，从12月下旬即第二个生长季后半期开始发病，在1月至2月气温较低、湿度较大时，晚疫病常常严重流行。在Sapa地区（北京高原），整个生长晚疫病对马铃薯作物都是主要威胁。在感病品种上病害的发生和严重度可达到100％。在大叨地区，在干旱季节（11－4月）晚疫病发生最轻，而在雨季（5－10月）严重流行。在越南，还未进行晚疫病菌生物学和流行学方面的基础研究。对晚疫病防治研究主要集中在筛选新的杀菌剂。大部分工作集中在抗病育种和抗病品种的筛选。目前需要进行晚疫综合治疗、流行学、晚疫病菌生物学和抗病育方面的深入研究和培训。  相似文献   

Natural hazards and genetic diversity in rice     

Stephen R. Morin  Marlon Calibo  Marilyn Garcia-Belen  Jean-Louis Pham  Florencia Palis 《Agriculture and Human Values》2002,19(2):133-149

Rice crop diversity hasdecreased dramatically in the recent past.Understanding the causes that underlie theevident genetic erosion is critical for thefood security of subsistence rice farmers andbiodiversity. Our study shows that farmers inthe northeastern Philippines had a markedreduction in rice diversity from 1996 to 1998.The ultimate causes were a drought resultingfrom the El Niño phenomenon in 1997 andflooding due to two successive typhoons in1998. The proximate causes, however, includedlocal water control factors, limitations in thehousehold and village-level seedinfrastructure, farm location in relation tothe goods and services necessary to obtainseeds, policies and programs of the Departmentof Agriculture, and the characteristics of therice varieties themselves. The implications ofour study are that genetic erosion is notalways the result of purposeful acts by farmersnor is it necessarily gradual. Improvingon-farm seed technology will stabilize the seedproduction, distribution, and use system andthereby enhance household food security.Ultimately, rice diversity will be improvedonly if diversity is a safe and viable optionfor farmers. Therefore, public policy thatsupports farmers who maintain a diverse set ofcultivars is critical for any on-farmconservation strategy.  相似文献   

Isolation and characterization of endophytic bacteria from wild and cultivated soybean varieties     

Pham Q. Hung  Senthil M. Kumar  V. Govindsamy  K. Annapurna 《Biology and Fertility of Soils》2007,44(1):155-162

Endophytic bacteria were isolated from surface sterilized stems, root, and nodules of wild and cultivated soybean varieties. Various phenotypic traits that are expected to be involved in the persistence and functions of the bacteria were analyzed. Most of the isolates from soybean were motile and indoleacetic acid producers, and 70 and 33% of isolates excreted cellulase and pectinase, respectively. These traits may be involved in endophytic characteristics in soybean. Some isolates were resistant to Str₁₀₀, formed capsules, and produced fluorescent pigments. Molecular characterization of selected 35 endophytic bacteria by 16S rDNA–polymerase chain reaction–restriction fragment length polymorphism showed two main clusters at 48 and 43% similarity coefficients in which most of the endophytes belonged. The genetic variation was more among endophytes isolated from Glycine max tissues than from G. soja.  相似文献   

An assessment of genetic diversity and population structures of fifteen Vietnamese indigenous pig breeds for supporting the decision making on conservation strategies     

Van Ba  Nguyen  Nam  Le Quang  Do  Duy Ngoc  Van Hau  Nguyen  Pham  Lan Doan 《Tropical animal health and production》2020,52(3):1033-1041

Tropical Animal Health and Production - The study aimed to characterize genetic diversity, genetic clusters, and phylogenetic relationships of 15 Vietnamese indigenous pig breeds across the country...  相似文献   

The phenotypic characteristics and relational database for Vietnamese native pig populations     

Shinya Ishihara  Fukuhiro Yamasaki  Pham Hai Ninh  Nguyen Cong Dinh  Aisaku Arakawa  Masaaki Taniguchi  Ngo Thi Kim Cuc  Satoshi Mikawa  Masaru Takeya  Kazuhiro Kikuchi 《Animal Science Journal》2020,91(1)

Although there are a number of Vietnamese native pig (VnP) populations, some are on the verge of extinction, and therefore adequate management and conservation are necessary. In this study, we conducted a field survey of VnP populations and analyzed interrelationships among their characteristics. We also established a relational database for management of field data on these populations. For data collection, we conducted interviews with farmers and visual inspection of 32 VnP populations in 22 provinces of Vietnam, as well as taking photographs of individual animals. Data on the characteristics of VnP populations were subjected to multiple correspondence analysis (MCA). For establishment of the database, normalization and table partitioning were performed to eliminate redundancy and ensure consistency of the collected data items. Passport data, characteristics data, and image data were collected from a total of 1,918 VnPs and entered as a normalized table. Upon MCA, most of the populations were not separated from each other, but the Mong Cai, O Lam, and Chu Prong populations were separated from the other populations. Thus, we have constructed a relational database from comprehensive information on the characteristics of VnP populations.  相似文献   

A soft technology to improve survival and reproductive performance of Litopenaeus stylirostris by counterbalancing physiological disturbances associated with handling stress     

Nelly Wabete  Liet Chim  Dominique Pham  Pierrette Lemaire  Jean-Charles Massabuau 《Aquaculture (Amsterdam, Netherlands)》2006,260(1-4):181-193

The consequences of handling stress (fishing, transfer, eyestalk ablation) on shrimp broodstock are poorly documented. The weakness of farmed shrimp, Litopenaeus stylirostris, during winter is a major problem in New Caledonia, because of seasonal climate (tropical–sub-temperate). The transfer of broodstock in winter from earthen outdoor ponds to indoor maturation tanks in the hatchery (T = 20 °C, Salinity = 35‰, fed shrimp) usually leads, after 48 h, to high mortality (up to 70%). Eyestalk ablation to induce ovarian maturation in females leads to further mortality.

Starting from a background analysis of physiological disturbances (initial osmoregulatory imbalance) associated with handling stress (Wabete, N., Chim, L., Lemaire, P., Massabuau, J.-C., 2004. Caractérisation de problèmes de physiologie respiratoire et d'échanges ioniques associés à la manipulation chez la crevette pénéide Litopenaeus stylirostris à 20 °C. Styli 2003. Trente ans de crevetticulture en Nouvelle-Calédonie. Ed. Ifremer. Actes Colloq. 38, 75-84.), we developed a protocol using a soft technology, based on modifications of water salinity, temperature and feeding regime. The aim was to minimize problems of osmoregulatory imbalance and associated mortalities. The protocol we developed, called the LSD OT protocol (Low Salinity and Diet, Optimal Temperature), was first evaluated on sub-adult shrimp (20–25 g) and then applied to broodstock. Survival after transfer and following eyestalk ablation, as well as reproductive achievement (spawning rate, nauplii number) was considerably improved when shrimps were transferred under “physiological comfort” i.e. warmed isosmotic water (26 °C and 26‰) and unfed for 3 d. This new handling protocol, based on a better control of salinity, temperature and feeding conditions, has been transferred successfully to private hatcheries and already contributes to an increased profitability of New-Caledonian shrimp industry.  相似文献