Evaluation of Different Substrates Compositions for Acclimatization of Tissue Culture Taro Plantlets in a Propagator

Taro is cultivated in most Regions of Cameroon and it is affected by taro leaf blight disease since 2010 which has decreased its production. Lack of disease-free planting materials has been a main problem to farmers. This study was carried out at International Institute of Tropical Agriculture (IITA) Yaounde and Institute of Agricultural Research for Development (IRAD) Bambui to assess different substrates for acclimatization of tissue culture taro plantlets in apropagator. No information is available on acclimatization of Cameroonian taro plantlets in different substrates. Taro plantlets from tissue culture were acclimatised in a propagator for six weeks under different substrates, the first substrate consisted of sterile three parts of soil and one part of river sand mixed together (3:1), the second substrate consisted of sterile two parts of soil and two parts of river sand mixed together (2:2), the third substrate consisted of sterile two parts of soil, one part of rice husk and one part of river sand mixed together (2:1:1) and the fourth substrate consisted of sterile one part of soil and three parts of river sand mixed together (1:3). After acclimatisation of the different taroplantlets (Dark green petiole with small leaves (L1), Red petiole with small leaves (L2), Light green petiole with large leaves (L3) and Light green petiole with small leaves (L4) in these four substrates, it was observed that the best growth rate of plant was recorded on substrate sand + soil (1:3). The other substrates showed moderate growth of plants. Substrate sand + soil (1:3) can be recommended for acclimatization of Cameroonian taro plantlets.

Pollen-inferred Holocene vegetation and climate histories in Taro Co,southwestern Tibetan Plateau

A 310-cm-long sediment core,covering the last10,200 years,was collected from Taro Co on the southwestern Tibetan Plateau and analyzed for pollen,grain size and total inorganic carbon content.The pollen data showed that vegetation changed from alpine steppe to alpine meadow during 10,200–8,900 cal a BP,to alpine steppe dominated by Artemisia during 8,900–7,400 cal a BP,to alpine meadow during 7,400–3,300 cal a BP and to alpine steppe after 3,300 cal a BP.Correspondingly,the pollen,grain size and total inorganic carbon content results revealed climatic change in this area over four stages.The initial stage was from 10,200 to 8,900 cal a BP,during which the climate changed from cold-dry to warm-humid.The second stage(8,900–7,400 cal a BP)was characterized by a warm and dry climate.However,at approximately7,400 cal a BP,the climate began to become cold and humid,which continued until 3,300 cal a BP.The last stage,from 3,300 cal a BP to present,was characterized as cold and increasingly arid.Climatic events of the early and mid-late Holocene showed that the area was significantly affected by the westerlies.However,the mid-Holocene climate in Taro Co was controlled by the Indian monsoon.The mid-late Holocene depositional environment record of Taro Co was very important to further elaborate the degree of influence by the westerlies or Indian monsoon.

Comparative Study on the Efficacies of 11 Chemical Agents against Taro Soft Rot Caused by Pectobacterium aroidearum

[Objective]The paper was to screen the effective agents for effectively controlling the occurrence and prevalence of taro soft rot.[Method]The fungicidal effects of 11 fungicides on taro soft rot were determined by inhibition zone method.[Result]0.3%Tetramycin,25%bromothalonil,3%Zhongshengmycin and 30%zinc thiazole had better antifungal effect on Pectobacterium aroidearum at recommended concentration.The indoor toxicity of four fungicides showed that the EC50 of 0.3%tetramycin AS was the smallest of 0.6μg/mL,indicating that tetramycin had the largest toxicity and the best inhibitory effect against P.aroidearum;followed by 25%bromothalonil EC and 3%Zhongshengmycin WP,with the EC_(50) of 2.57 and 97.72μg/mL,respectively;the inhibitory effect of 30%zinc thiazole SC against P.aroidearum was the poorest.[Conclusion]The study provides a reference for screening out new and efficient chemical agents against taro soft rot.

Effect of Different Concentrations of Orange Juice for in Vitro Regeneration and Multiplication of Cocoyam (Taro)

Taro (Colocasia esculenta) and tannia (Xanthosoma sagittifolium) are commonly referred to as cocoyam in Nigeria. They are cherished for their rich taste, nutritional and medicinal properties. Traditionally, cocoyams are vegetatively propagated from tuber fragments, a practice that encourages pathogen distribution. For rapid multiplication and production of quality planting materials, tissue culture technology offers promising alternative compared to the traditional production methods. In this study different concentrations of ripped sweet orange (Citrus sinensis) juice were screened for regeneration and multiplication of 2 months old in vitro cocoyam shoot explants. Among the concentrations, maximum numbers of roots (37 ± 5) were observed in Murashige and Skoog (MS) medium supplemented with 10% orange juice after 8 weeks in culture compared to 16 ± 4 (roots) observed in the control medium. On shoot multiplicity, 16 ± 3 shoots were induced in the control medium in contrast to 12 ± 0.8 shoots in the MS medium supplemented with 10% orange juice after 8 weeks of culture. Higher concentrations (25% and 35%) of the orange juice supplemented medium resulted in concomitant inhibition of all the growth parameters. The study successfully established that ripped orange juice could substitute the use of conventional growth hormones cytokinins (BAP) and auxins (NAA) in in vitro regeneration and rapid multiplication of cocoyam shoot explants.

Effect of Processing on the Oxalate and Calcium Concentrations of Two Local Dishes, Cơm Hến and Canh Chua Bạc Hà, Prepared from Taro Stems

Stems of sweet taro (Colocasia esculenta) grown in Thua Thien HuếProvince in Vietnam and were used as an ingredient to prepare two local dishes, Cơm Hến and Canh Chua Bạc Hà. This study investigated the effect of simple processing treatments used to prepare these popular dishes on the total, soluble and insoluble oxalate and calcium contents of the taro stems. Raw stems were used to prepare Cơm Hến. Three treatments, removing the skin then washing and slicing, slicing and washing, or slicing and then allowing the stems to wilt overnight were compared to the whole raw stems with the skin retained. Overall, processing the stems reduced the soluble oxalate contents by a mean of 8% when compared with the original raw stems. The mean total calcium bound in the insoluble oxalate fraction of the three processing treatments was 43.3% ± 2.0%. Canh Chua Bạc Hà was prepared by boiling peeled taro stems. In this experiment the peeled stems were boiled for 10, 15 and 20 min and this resulted in 63.4%, 74.5% and 76.6% reductions in soluble oxalate content, respectively, when compared to the original peeled stems. Boiling for 20 min was the most effective way to reduce both the total and soluble oxalate contents of the stems. 39% of the total calcium in the raw taro stems was bound to the insoluble oxalate fraction and this was reduced to a mean of 17.2% ± 2.6% by the three cooking treatments.

Analysis of Climate Suitability of Lipu Taro Planting in Lipu County

Based on the analysis of planting situation, climatic characteristics and field management technology of Lipu taro in each growth period, climate suitability of Lipu taro was studied. The results show that temperature affects the growth of Upu taro most greatly, and sunshine hours and precipitation also influence it obviously. In order to make Lipu taro develop well, it is necessary to utilize climate resources rationally and strengthen the control of diseases and insect pests and field management.

Preliminary Assessment of Genetic Diversity in Three Taro （Colocasia esculenta L, Schott） Landraces Using Agro-morphological and SSR DNA Characterisation

Taro （Colocasia esculenta L. Schott） is an important underutilised crop in South Africa, East Africa and Indonesia. Three taro landraces, namely, Dumbe Lomfula （wild）, KwaNgwanase and Umbumbulu, were collected from two locations in KwaZulu-Natal （KZN）, South Africa, and planted at two locations, Pietermaritzburg （KZN） and Roodeplaat, Pretoria. Ago-morphological characterisation of vegetative and corm characteristics were done four months after planting and at harvest, respectively. Sampling for DNA fingerprinting using five SSR primers was done using leaf material four months after planting. Agro-morphological characterisation was useful in showing differences between the wild landrace and the two cultivated landraces, as well as identification of dasheen and eddoe types. SSR primer characterisation showed that despite significant morphological difference, the wild Dumbe Lomfula and Umbumbulu landraces were closely related but different from the KwaNgwanase landrace. Although landraces showed great morphological variation, this did not necessarily imply genetic variation. It is concluded that SSR primers are more useful for characterising taro landraces.

Fluorine in Water and Dental Fluorosis in a Community of Queretaro State Mexico

The community La Llave, Queretaro State, Mexico, has not been identified by the sanitary authorities as living in a hazard area related to dental fluorosis. However;a high concentration of fluoride is found in their drinking water causing them dental fluorosis. Physical-chemical analysis was carried out in the groundwater sources to determine the prevalence of dental fluorosis risk and caries accordingly to criteria of The World Health Organization, and 154 school children of ages 10 to 13 years were examined. As a result, 1.9 mg/L of fluorine concentration in drinking water was obtained;dental fluorosis presence was detected in the school children with an incidence of about 98%, in 47% of cases severe fluorosis with a dental caries index of 3.06 was traced. The groundwater sources in La Llave community contains fluorine above the limits dictated by Mexican regulations, producing serious repercussions on the health of school children, with an unnaturally high incidence of dental fluorosis.

Control Effect and Application Technology of Mandipropamid on Red Taro Blight

The field experiment results showed that 250 g/l mandipropamid suspension had good control effect on red taro blight,and the 1∶1500 suspension was applied twice continuously during the early period( June 25) and culmination period( July 12) of taro blight; the control effect 23 d after the last application reached 79. 28%,significantly better than that of conventional pesticide,and it was safe,so it had good prospects for the development and application in production.

Effect of Pre-Gelatinization Conditions on the Total Oxalate Content and Techno-Functional Properties of Taro (Colocasia esculenta) Flour

Like most roots and tubers, taro (Colocasia esculenta) corms have a short shelf-life due to the high moisture content, which aggravates their post-harvest losses. They also contain high amounts of calcium oxalates, limiting their use in food applications. To help add value and diversify the use of taro corms as well as curb food losses, various strategies have been proposed, such processing of the corms into flour. This study aimed at evaluating the total oxalate content and techno-functional properties of taro flour as affected by the pre-gelatinization conditions (i.e., method and time). Pre-gelatinized taro flour was prepared by subjecting peeled and cleaned taro corms to roasting (190°C), boiling (100°C), and steaming (100°C) for 10 min, 20 min and 30 min, respectively, for each method, followed by drying at 55°C and milling. Generally, all the properties of flour were significantly affected by the pre-gelatinization conditions (P 0.05). The total oxalate content of the pre-gelatinized taro flour ranged from 33.26 to 76.90 mg/100g. Pre-gelatinization by boiling significantly reduced the oxalate content (56.7%), while roasting resulted in the least reduction (36.2%). The flour colour i.e. L*, hue, and chroma ranged from 38.47° - 70.30°, 42.64° - 69.43°, and 7.78° - 10.58°, respectively. Roasting resulted in flour with the largest L* (70.30°) and hue angle (69.43°). Boiling also resulted in flour with the highest bulk density (BD) (0.86 g/cm3) and the lowest water solubility index (WSI) (9.39%). Steamed flour had the highest water absorption index (WAI) (3.81 g/g), water holding capacity (WHC) (4.59 g/g), and swelling capacity (SC) (4.86 g/g). This study shows that pre-gelatinization (i.e. by boiling, steaming or roasting) significantly affects the total oxalate content and techno-functional properties of taro flour, which in turn influences its use in other food applications thus increasing the utilization and production of taro simultaneously.

Molecular Detection of Phytophthora colocasiae of Taro Leaf Blight Based on PCR

The present PCR assay was conducted to develop rapid and sensitive detection of Phytophthora colocasiae,in order to provide a robust and reliable tool for healthy seedling production of taro and limiting the transmission and spread of the causal organism of taro leaf blight in taro planting regions.The samples were used to extract total DNA and to be detected by PCR with P.colocasiae specific primer pairs PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.Distinct fragments of about 200 bp and 240 bp were amplified by PCR using primers PCSP-RL F/PCSP-RL R and PCSP-T F/PCSP-T R,respectively.The analysis of the nucleotide sequence of the PCR products were found to be 99% identical to sequence of RAS-related protein (Ypt1) and phospho-ribosylanthranilate isomerase (TRP1) in P.colocasiae,respectively.It is concluded that rapid and sensitive developed PCR assay for detection of P.colocasiae could be used in routine diagnosis and aid in management practices to mitigate taro leaf blight.

Dynamic Characteristics of Growth and Development of Xiangsha Taro in Jingjiang

The growth and development of Jingjiang Taro [Colocasia esculenta（L.） Schott] were observed, laying foundation for highly-yielding cultivation technology system of Xiangsha taro. The results indicate that germination of the second taro happened from 46 d after sprouting （7-8 leaves）; the first taro began to expand, from 125 d after sprouting （12 leaves） when the the second taro was been formed; the third taro began to form from 141 to 150 d after sprouting （15-16 leaves）. The fresh weight of the second and third taros quickly increased from the time of 15 leaves to harvest. Early September is a transformation term of Xiangsha taro from vegetative body dominant to corm growth dominant.

Multitemporal landslide inventory analysis of an intertropical mountain in west-central Mexico——Basis for hazard management

Landslides in intertropical mountainous areas of Mexico are a natural hazard that could potentially generate a disaster. Despite this, many areas lack landslide inventories, making it difficult to monitor and efficiently manage the associated risks for local populations. For this reason, the aim of this research was to undertake a multitemporal landslide inventory and analyze its conditioning factors in the Pico de Tancítaro stratovolcano, which, in recent decades, has presented several high-risk geomorphological events with disastrous consequences for nearby localities. The spatial distribution of landslides and its conditioning factors were mapped at a 1:50,000 scale for the 1995-2020 period, through visual interpretation of orthophotos and satellite images(Landsat, SPOT, and SENTINEL). The conditioning factors that link the most to landslides were Quaternary andesite and basaltic andesite rocks;volcanic cones, mountain river valleys, and very steep to steep slopes(30° to >45°), oriented to the South, North, and East;Andosols and Leptosols;and the oyamel fir and mixed forests. 505 landslide events classified into slides and flows that occurred in 1995, 2004, 2010, and 2015 were identified. New scars generated by the reactivation of landslide processes were also observed. The landslides in the study area were triggered by torrential rains caused by hurricanes and tropical storms;such as hurricanes Alex and Patricia. The inventory and analysis of conditioning factors highlighted the distribution and dynamics of slides and flows in the study area. In addition, the most important factors for studies of landslide susceptibility, hazards, and risks in the Pico de Tancítaro stratovolcano were identified, contributing to the management of geomorphological risks in intertropical mountain areas.

Public Deliberation in an Age of Visibility： Political Communication Analysis in Mexico

This paper reviews the importance of visibility in public deliberation in the theoretical construction of political communication. Political communication is the area that study social and political interactions of actors through discourses and practices within the public sphere. The social and political actors manage their public appearances in an exercise of visibility, allowing deliberation of public affairs. In recent years, Mexico has been a relevant case of study for understanding the opening of media into the public discussion of governmental affairs. As an example, this paper presents an analysis of public deliberation in the city of Quer6taro, Mexico. This study analyses political participation and openness of media, based on the concepts visibility, public sphere and citizenship. The analysis was built on the idea that the press concentrates most of the issues of public interest and that it reflects actors and arguments given for deliberation. In a qualitative approximation, we analyzed the discourses published in four journals and developed an analytical framework that illustrates the levels of access and visibility of a variety of political and social actors. This exercise demonstrates the importance of the concept of visibility in public deliberation and the media as managers in the current configuration of political communication.

Genetic Diversity of Taro Landraces from Côte d’Ivoire Based on Qualitative Traits of Leaves

Taro is an important crop species in Côte d’Ivoire. It is cultivated for its tubers and leaves. But its knowledge and genetic diversity and differentiation are very weakly documented. Several morphological types are found in rural area, but their identification is not very clear, and their agronomic potentiality is underexploited. In this context we initiated a survey and collected 213 accessions from 14 growing regions of Côte d’Ivoire. The diversity was evaluated based on seven qualitative traits of leaves (Shape of the base of the leaf, Predominant position (shape) of the leaf blade surface, Margin of the leaf blade, Leaf blade variegation, Profile of the petiolar junction, Shape of the leaf sheath, Shape of the appendix) during an experimentation conducted in rural area. The objective of this study was to characterize the collection of taros collected in different geographical zones of Côte d’Ivoire and identify the genera cultivated. Results of our study indicated that excepted margin of the leaf blade all traits are very discriminant. Several variants were observed for each of traits. According to observations and statistics analysis accessions were separated into two main groups. The characteristics of these groups indicate that taro cultivated in Côte d’Ivoire could belong to two genera: Xanthosoma and Colocasia.

青藏高原西南部塔若错湖泊沉积物记录的近300年来气候环境变化

以青藏高原西南部塔若错的34cm浅湖芯为研究对象,对其沉积物样品进行总有机碳、无机碳、总氮、微量元素、正构烷烃含量及碳氮比等多项指标的分析测定。采用过剩210 Pb和137 Cs计年法对该湖芯进行了定年和沉积速率研究,获得了近300年的连续湖泊沉积环境序列。在明确了各指标气候环境指示意义的前提下,综合对比分析湖芯中各项气候环境指标,并结合定年结果重建了塔若错湖区近300年来的气候环境变化。结果表明:塔若错湖区气候环境变化可分为3个明显阶段:早期为1705～1778年,该地区气候环境温暖湿润,湖区植被广泛发育;中期为1778～1860年,湖区处于小冰期末次阶段,气候环境寒冷而湿润,植被发育受阻;后期为1860年至今,为小冰期结束后偏暖干化时期。其中,后期又可分为3个亚阶段:1860～1924年,湖区气候环境稍暖且干旱,植被稍有发育;1924～1969年,湖区气候环境呈现偏冷干特点,植被发育暂缓;1969年至今,湖区气候回暖,环境干旱化有所缓解,植被开始逐渐发育。在气候冷暖变化上,该湖芯记录与古里雅冰芯记录和青海湖湖泊沉积记录都有较好的可对比性,只是在起讫年代上存在一些差异。

Risk Assessment of Agricultural Products Supply-Chain Finance Based on D-S Theory

Agricultural products supply-chain finance, as one of the solutions to the issue of “capital problems” of agriculture, countryside and farmers, has proposed a kind of characteristics model to assess the risk of agricultural production, processing and marketing, which can improve the issue of farmers and enterprises lacking of funds. This model is proposed on the basis of uncertain information processing method of D-S theory and its data combination rules, combined with the “discount rate” correction model, and it includes a risk assessment index system of agricultural products supply-chain finance, fully considering the five aspects of production, processing, marketing, cooperation of supply chain and collateral. At last, a taro supply chain is taken for example. And the risk assessment of its supply-chain finance based on this model has been discussed in detail. And the result has proved that the model and its algorithm are practical and feasible.

^14CO2 Fixation and Translocation of Photoassimilates as Selection Criteria of Egyptian Taro Genotypes

The growth characterlstlcs, different physlological parameters, photosynthetic activity （^14CO2 fixation）, and the translocatlon rate of photoassimllates In different taro （Colocasia esculenta L. Schott） genotypes was studled In order to determlne the posslble use of these parameters as selectlon crlterla for dlfferent wldely used genotypes of taro （Delta No. 9, 15, 20, 21, and balady）. The results obtalned suggest that Delta No. 21 shows the most slgnlflcant increase In all parameters tested compared wlth the control （balady）, followed by Delta No. 9, 15, and 20, respectively. The results show a positive correlation between photosynthetlc actlvlty, translocatlon efflclency, and total yield. The selected clone Delta No. 21 Is recommended for cultlvatlon In the delta reglon of Egypt.

识别手写字体自动建模书法机器人

基于大规模实时文字处理,海量文字录入以及模仿个人笔迹等应用需求,设计识别手写字体自动建模书法机器人,采用微信小程序与下位机结合的框架,通过与写字机器人上的8266Wi-Fi芯片建立WebSocket进行数据通信。基于OpenCV的轮廓检测进行字符提取,通过训练分类器和样本文件识别文字。采用onActivityResult回调处理,实现拍照录入字体,基于Taro+React框架适配不同小程序平台,完成手写字体的识别与自动建模。写字机器人机械结构采用Hbot机械控制结构,采用前梯形加减速控制与Bresenham直线算法相结合实现对机构的运动速度规划。经过对识别系统的600次测试,字库识别准确率可达92%,模仿笔迹自动建模准确率可达83%。

Sugar Coated Taro

Taro is smooth and sticky in texture and rich in fat,protein and sugar.According to Chinese traditional medicine, taro nourishes the spine and stomach and helps energy. Ingredients:500 grams taro (peeled and chopped into diamond-shaped cubes), 15 grams sugar. 250 grams vegetable oil. Method: 1. Heat oil in a wok and add taro cubes. Fry unti they turn golden brown. 2. Take out the taro with a sieve and pour the oil into a container for later use. Add sugar and one tablespoon oil.Stir continuously to prevent burning. When