scholarly journals Multi-genotype varieties reduce rice diseases through enhanced genetic diversity and show stability and adaptability in the field

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Ping He ◽  
Cong Wang ◽  
Neng Zhang ◽  
Bin Liu ◽  
Yang Yang ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Disease Resistance ◽  
Agricultural Development ◽  
Production Systems ◽  
Field Trials ◽  
Blast Disease ◽  
Rice Varieties ◽  
Rice Plants ◽  
Disease Occurrence ◽  
The Relationship

AbstractRice is a crucial food crop worldwide. The genetic diversity in rice germplasm indicates its promising potential utilization in disease and pest control. To explore the relationship between genetic diversity and disease resistance in rice plants, multi-genotype rice varieties developed from multi-parent advanced generation inter-cross (MAGIC) population lines were used here to analyze the correlation between disease occurrence and genetic diversity, as well as for field monitoring of their disease occurrences and yields. We found that genetic diversity and disease resistance of the multi-genotype varieties tested in this study were superior to those of their component lines and mono-genotype varieties, and the incidence of rice blast disease decreased as the genetic diversity of multi-genotype rice varieties increased. We further conducted field trials using these multi-genotype varieties for three years in different rice-planting areas. The results showed that multi-genotype varieties exhibited good disease resistance and high-yielding potential. Thus, proper use of multi-genotype varieties characterized by rich genetic diversity is a promising approach to improve disease resistance of rice plants in agricultural production systems and is of great significance for ensuring food security and achieving sustainable agricultural development.

scholarly journals Exploring the Distribution of Blast Resistance Alleles at the Pi2/9 Locus in Major Rice-Producing Areas of China by a Novel Indel Marker

Plant Disease ◽  
2020 ◽  
Vol 104 (7) ◽  
pp. 1932-1938
Author(s):  
Dagang Tian ◽  
Yan Lin ◽  
Ziqiang Chen ◽  
Zaijie Chen ◽  
Fang Yang ◽  
...  
Keyword(s):  
Blast Resistance ◽  
Resistance Breeding ◽  
Field Trials ◽  
Indel Marker ◽  
Blast Disease ◽  
Cereal Crops ◽  
R Genes ◽  
Rice Varieties ◽  
Environment Friendly ◽  
The World

Rice blast disease caused by the fungus Magnaporthe oryzae damages cereal crops and poses a high risk to rice production around the world. Currently, planting cultivars with resistance (R) genes is still the most environment-friendly approach to control this disease. Effective identification of R genes existing in diverse rice cultivars is important for understanding the distribution of R genes and predicting their contribution to resistance against blast isolates in regional breeding. Here, we developed a new insertion/deletion (InDel) marker, Pigm/2/9InDel, that can differentiate the cloned R genes (Pigm, Pi9, and Pi2/Piz-t) at the Pi2/9 locus. Pigm/2/9InDel combined with the marker Pi2-LRR for Pi2 was applied to determine the distribution of these four R genes among 905 rice varieties, most of which were collected from the major rice-producing regions in China. In brief, nine Pigm-containing varieties from Fujian and Guangdong provinces were identified. All of the 62 Pi2-containing varieties were collected from Guangdong, and 60 varieties containing Piz-t were from seven provinces. However, Pi9 was not found in any of the Chinese varieties. The newly identified varieties carrying the Pi2/9 alleles were further subjected to inoculation tests with regional blast isolates and field trials. Our results indicate that Pigm and Pi2 alleles have been introgressed for blast resistance breeding mainly in the Fujian and Guangdong region, and Pi9 is a valuable blast resistance resource to be introduced into China.

scholarly journals Pendugaan Intensitas Serangan Penyakit Blas pada Tanaman Padi Melalui Pendekatan Citra NDVI (Normalized Difference Vegetation Index)

2019 ◽  
Vol 7 (2) ◽  
pp. 287
Author(s):  
I Made Prasetia Candra Andika ◽  
I Made Anom Sutrisna Wijaya ◽  
Ida Bagus Putu Gunadnya
Keyword(s):  
Vegetation Index ◽  
Normalized Difference Vegetation Index ◽  
Technology Development ◽  
Blast Disease ◽  
Aerial Photo ◽  
Rice Plants ◽  
Processing Data ◽  
Arc Gis ◽  
The Relationship ◽  
Attack Intensity

Penyakit blas merupakan salah satu penyakit yang berbahaya bagi tanaman padi. Penyakit ini bisa menyerang di setiap fase pertumbuhan. Perhitungan intensitas serangan penyakit blas saat ini masih  dilakukan secara manual. Diperlukan pengembangan teknologi dalam pendugaan intensitas serangan penyakit blas melalui citra NDVI. Penelitian ini bertujuan untuk (1) untuk mendapatkan ketinggian foto udara NDVI terbaik, (2) untuk mendapatkan umur tanaman padi dengan intensitas serangan penyakit blas tertinggi, (3) untuk mendapatkan hubungan antara intensitas serangan penyakit blas dengan nilai NDVI tanaman padi. Penelitian ini menggunakan Drone DJI Phantom 4 dengan lensa NDVI. Pengolahan data menggunakan Web Drone Deploy dan software Arc Gis 10.3. Berdasarkan dari hasil analisis, detail terbaik dari pembesaran 200% mendapatkan akuisisi ketinggian dari citra NDVI adalah 20 meter dengan ukuran piksel 1,4732 cm/pixel. Pertumbuhan intensitas serangan penyakit blas tertinggi  terjadi pada umur 98 hari setelah tanam. Hubungan antara intensitas serangan penyakit blas dengan nilai NDVI memiliki koefisien determinasi sebesar 0,986. Persamaan regresi didapatkan dalam penelitian ini adalah y = -23345x3 + 21191x2- 6416,8x + 665,07 dengan akurasi sebesar sebesar 91,74%.   Blast is one of disease that is dangerous for rice plants. This disease can attack in every phase of growth. Calculation of the intensity of blast disease attacks is still done manually. Technology development is needed in estimating the intensity of blast disease attacks through NDVI imagery. This study purpose (1) to get the best NDVI aerial photo altitude, (2) to get the age of rice plants with the highest attack intensity of blast disease, (3) to get a relationship between the intensity of blast disease and the NDVI value of rice plants. This study use Drone DJI Phantom 4 with lens NDVI. Processing data using Web Drone Deploying and Arc Gis 10.3 software. Based on the analysis results, the best detail of 200% zooming results obtained altitude of the NDVI image acquisition that is 20 m with pixel density of 1,4732 cm/pixel. The highest intensity of blast disease attacks occurs at the age of 98 days after planting. The relationship between the intensity of blast disease and NDVI value has a determination coefficient of 0.986. The regression equation obtained in this study is y = -23345x3 + 21191x2- 6416,8x + 665,07 with an estimated accuracy of 91,74%.

scholarly journals KERAGAMAN DAN SUMBER GEN KETAHANAN VARIETAS PADI LOKAL TERHADAP PATOGEN Pyricularia grisea PENYEBAB PENYAKIT BLAS

2020 ◽  
Vol 22 (2) ◽  
pp. 119-128
Author(s):  
Santoso Santoso ◽  
Anggiani Nasution ◽  
Nani Yunani
Keyword(s):  
Genetic Diversity ◽  
Blast Disease ◽  
Pyricularia Grisea ◽  
Specific Response ◽  
Response Patterns ◽  
Rice Varieties ◽  
High Genetic Diversity ◽  
Resistance Response ◽  
Pathogenic Races ◽  
Moderately Resistant

[DIVERSITY AND THE SOURCE OF RESISTANCE GENE OF LOCAL RICE VARIETIES ON THE PATHOGENIC OF Pyricularia grisea CAUSE OF BLAST DISEASE]. Local rice varieties are known to have resistance or source of genes to  pests even though their productivity yield is low. The pathogen of Pyricularia grisea is a cause of blast disease, which is one of the obstacles in rice production. The research aims to characterize the resistance of local rice varieties to the  pathogen of P. grisea and to evaluate the virulence level of P. grisea pathogens against local rice varieties. A total of 100 local rice varieties and check varieties are susceptible and resistant namely Kencana Bali and Situ Patenggang tested their resistance to 4 dominant pathogenic of P. grisea i.e. races 033, 073, 133 and 173. Inoculation was carried out on stages 4-5 leaves or 18-21 days after seedling in a green house. The results showed a high genetic diversity of local rice varieties against pathogenic races 033, 073, 133 and 173. Based on the response of local rice varieties resistance i.e. moderately resistant (MR), resistant (R) and susceptible (S) to pathogenic races 033, 073 , 133 and 173 obtained 45 resistance response patterns. Cere Bereum varieties which are local rice varieties from West Java and Situ Patenggang resistant check varieties have a resistant response to 4 P. grisea pathogenic races used. A number of local rice varieties also show a resistant and moderately resistant response to the four pathogenic races used include Siam 11, Pare Siriendah, Menyan, Cere Manggu and Enud-Rawa Bogo. Local rice varieties Djedah and Padi Hitam (2) are local rice varieties that have a specific response of resistant or moderately resistant to race 173.  Race 133 and 173 have higher virulence rates than those of races 033 and 073 on local rice varieties. The results of this study indicate that there is a great potential for the utilization of local rice varieties, as a source of resistance genes for blast disease for the assembly of rice varieties that are resistant to blast disease.   

scholarly journals Population Structure of Phytophthora infestans in the Toluca Valley Region of Central Mexico

2001 ◽  
Vol 91 (9) ◽  
pp. 882-890 ◽  
Author(s):  
Niklaus J. Grünwald ◽  
Wilbert G. Flier ◽  
Anne K. Sturbaum ◽  
Edith Garay-Serrano ◽  
Trudy B. M. van den Bosch ◽  
...  
Keyword(s):  
Genetic Diversity ◽  
Phytophthora Infestans ◽  
Production Systems ◽  
Allozyme Data ◽  
Land Race ◽  
Disease Occurrence ◽  
Cultivated Potatoes ◽  
Toluca Valley ◽  
Solanum Spp ◽  
Wild Solanum

We tested the hypothesis that the population of Phytophthora infestans in the Toluca valley region is genetically differentiated according to habitat. Isolates were sampled in three habitats from (i) wild Solanum spp. (WILD), (ii) land-race varieties in low-input production systems (RURAL), and (iii) modern cultivars in high-input agriculture (VALLEY). Isolates were sampled in 1988-89 (n= 179) and in 1997-98 (n= 389). In both sampling periods, the greatest genetic diversity was observed in RURAL and VALLEY habitats. Based on the Glucose-6-phosphate isomerase and Peptidase allozymes, the subpopulations from the three habitats were significantly differentiated in both sampling periods. In contrast to allozyme data for 1997-98, no differences were found among the three subpopulations for sensitivity to metalaxyl. Two groups of isolates identical for allozyme and mating type were further investigated by restriction fragment length polymorphism fingerprinting; 65% of one group and 85% of another group were demonstrated to be unique. The genetic diversity data and the chronology of disease occurrence during the season are consistent with the hypothesis that populations of P. infestans on wild Solanum populations are derived from populations on cultivated potatoes in the central highlands of Mexico near Toluca.

Population - an element of agricultural development in Serbia

Stanovnistvo ◽  
1999 ◽  
Vol 37 (1-4) ◽  
pp. 141-161
Author(s):  
Marina Todorovic ◽  
Gordana Vojkovic
Keyword(s):  
Agricultural Production ◽  
Regional Differences ◽  
Agricultural Development ◽  
Historical Review ◽  
Working Population ◽  
Theoretical Level ◽  
Level Of Education ◽  
Agricultural Producer ◽  
The Impact ◽  
The Relationship

The author begins by discussing the relationship between agriculture and population at a theoretical level, proceeds with a historical review of changes in the role and significance of an individual as agricultural producer, and finally, analyzes population as an element (potentials - limitations) of agricultural development in Serbia. The overall production results, and particularly the propensity to technical and technological innovation, as well as the ability to adapt to the changed conditions are, as we know well, crucially dependent on the structure of the working population. Hence, the author discusses regional differences in agricultural population by age, sex, level of education and productivity to provide a clear illustration of the impact of this element (indicator) on the population as the factor of agricultural production. The results show significant macroregional differences by this element with respect to the average for Serbia.

Preliminaries

2017 ◽  
Author(s):  
David J. Lobina
Keyword(s):  
Data Structures ◽  
Production Systems ◽  
Specific Data ◽  
Recursive Functions ◽  
Recursive Solution ◽  
Partial Recursive Functions ◽  
Recursive Structures ◽  
Recursive Data Structures ◽  
Recursive Data ◽  
The Relationship

Recursion, or the capacity of ‘self-reference’, has played a central role within mathematical approaches to understanding the nature of computation, from the general recursive functions of Alonzo Church to the partial recursive functions of Stephen C. Kleene and the production systems of Emil Post. Recursion has also played a significant role in the analysis and running of certain computational processes within computer science (viz., those with self-calls and deferred operations). Yet the relationship between the mathematical and computer versions of recursion is subtle and intricate. A recursively specified algorithm, for example, may well proceed iteratively if time and space constraints permit; but the nature of specific data structures—viz., recursive data structures—will also return a recursive solution as the most optimal process. In other words, the correspondence between recursive structures and recursive processes is not automatic; it needs to be demonstrated on a case-by-case basis.

scholarly journals Farmers’ knowledge and perception of finger millet blast disease and its control practices in western Kenya

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Wilton Mbinda ◽  
Agnes Kavoo ◽  
Fredah Maina ◽  
Margaret Odeph ◽  
Cecilia Mweu ◽  
...  
Keyword(s):  
Finger Millet ◽  
Management Practices ◽  
Smallholder Farmers ◽  
Descriptive Analysis ◽  
Wide Distribution ◽  
Blast Disease ◽  
Eastern Africa ◽  
Planting Density ◽  
Global Food Security ◽  
Disease Occurrence

Abstract Background Finger millet blast disease, caused by Pyricularia oryzae, is a serious constrain of finger millet production which is threatening global food security especially to the resource poor smallholder farmers in arid and semi-arid regions. The disease adversely affects finger millet production and consumption due to its wide distribution and destruction in all finger millet growing areas of southern Asia and eastern Africa. Here, we present a study that investigated the occurrence, impact, risk factors and farmers’ knowledge and perceptions of finger millet blast in Kenya. Methods We surveyed blast disease occurrence and interviewed farmers in Bungoma and Kisii Counties of Kenya during March–April 2019. Data were analysed using SPSS statistical program. Descriptive analysis was done by calculating means, percentages, frequencies, and standard errors. Comparative statistics, chi-square and t-tests, were used to evaluate differences existing among the farm characteristics and socio-demographics and the knowledge and perceptions of blast disease and its management practices. Results Our results show that blast disease is prevalent in all surveyed areas and adversely affects the productivity of the crop leading to poor yields. The disease occurrence varied from 92 to 98%, and was significantly higher in the major finger millet growing areas compared to the minor ones. Blast occurrence was associated with rainfall, altitude, planting density, intercropping and other farming practices. In all the surveyed regions, farmers had little knowledge about blast disease identification, its detection and spread. Further, the farmers’ awareness of blast disease control was inconsistent with established practices. Conclusions Our results show mitigation of finger millet blast disease should aim at improving farmers’ adoption of best practices through development of acceptable blast-resistant finger millet varieties, use of sustainable disease management practices, fostering linkages and creating new partnerships in the production-supply chain and maintaining a functional seed system. Findings from this study provide essential insights for effective decision making and management of the disease. This is fundamental to sustainable and secure food and income for finger millet growing farmers in Kenya.

scholarly journals The formation conditions of birch tar in oxygen-depleted environments

2021 ◽  
Vol 13 (6) ◽  
Author(s):  
Tabea J. Koch ◽  
Patrick Schmidt
Keyword(s):  
Temperature Interval ◽  
Production Systems ◽  
Technical Skills ◽  
Middle Palaeolithic ◽  
Dry Distillation ◽  
Narrow Temperature Interval ◽  
Glass Tubes ◽  
Formation Conditions ◽  
The Relationship ◽  
Heating Duration

AbstractBirch tar is the oldest manmade adhesive dating back to the European Middle Palaeolithic. Its study is of importance for understanding the cognitive capacities and technical skills of Neanderthals and the aceramic production systems employed in the European Palaeolithic and Mesolithic. Several methods may have been used to make birch tar, the most common proposition being dry distillation in oxygen-depleted atmospheres. One of the major impediments for our understanding of the conditions employed to make Neanderthal birch tar, and ultimately the technique used, is that it remains unknown at which temperatures exactly birch tar forms. The relationship between heating duration and tar formation is also unknown. To address these questions, we conduct a laboratory heating experiment, using sealed glass tubes and an electric furnace. We found that birch tar is only produced at a narrow temperature interval (350 °C and 400 °C). Heating times longer than 15 min have no effect on the quantity of tar produced. These findings, notwithstanding previous propositions of necessarily long heating times and larger tolerances for temperature, have important implications for our understanding of the investment in time needed for Palaeolithic birch tar making.

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