Thai Agricultural Research Journal

Genetic Diversity and DNA Fingerprint of Pineapple (Ananas comosus) Using SSR Markers

2024-02-23T13:16:01+07:00

The research and development of pineapple varieties in order to obtain good yield and quality, resistance to disease and insects, breeders need to have sufficient information about breed varieties and their genetic diversity to make a decision on selecting appropriate parents. This research aimed to assess the genetic diversity and analyse a cluster of 57 pineapple cultivars/lines from DOA germplasm collection using 20 fluorescent-labeled SSR markers, was conducted from October 2021 to September 2023. Results showed that all 20 SSR markers were able to differentiate genetically among pineapple cultivars/lines used in this experiment, generating a polymorphic allele in total of 105 alleles varying from 3 to 9 alleles per locus, with an average of 5.3 alleles per locus. All of 105 alleles showed that the polymorphic bands accounted for 100%. The sizes of DNA fragments ranged from 94 to 400 base pairs. The Polymorphism Information Content (PIC) value ranged from 0.44 to 0.67, with an average of 0.59. Cluster analysis based on UPGMA and genetic relationships using NTSYSpc version 2.10e showed similarity coefficient value in range of 0.50 to 1.00, and revealed 5 distinct groups, consistent with pedigree and the grouping of cultivars/lines based on morphological characteristics, with a cophenetic correlation (r) of 0.85. Therefore, SSR markers used in this study were appropriate to identify the genetic differences between pineapple cultivars/lines and the uniqueness of the cultivars in this experiment. Besides, the genetic diversity database of pineapples is useful for parental selection in pineapple breeding programs.

Comparison of Cassava Lines/Varieties and Proper Harvesting Period for Processing to French Fries

2023-11-30T11:25:58+07:00

French fries are a popular snack in Thailand. Generally, French fries are made from potatoes. The price of potatoes in Thailand is quite high. Replacing potatoes with cheaper cassava to produce French fries could promote and increase the use of cassava in Thailand. Six cassava lines/varieties CMRE60-03-02, CMRE60-03-13, OMRE60-02-61, OMRE60-03-09, Hanatee and Rayong2 at harvesting periods of 8, 10 and 12 months were compared on yield, texture and taste after processing to French fries. The experiments were conducted in three fields. In each field, a randomized complete block design was used. The treatments in each field were the planting of six cassava lines/varieties with four replications. Cassava lines/varieties in all fields were planted on the same date and harvested at 8, 10 and 12 months after planting, respectively. Results showed that at a harvesting period of 8 months, the OMRE60-02-61 line gave a fresh root yield of 2,877 kg/rai, close to Hanatee. Cassava French fries from the OMRE60-02-61 line had a slightly higher quality of texture hardness than that of the Hanatee variety and had a better score of consumer acceptance in terms of appearance, color, taste, texture and overall acceptability than those of the Hanatee variety. At a harvesting period of 10 months, the CMRE60-03-13 line gave a fresh root yield of 2,929 kg/rai, which was 31% higher than that of the Hanatee variety. Cassava French fries from the CMRE60-03-13 line had an equal score of consumer acceptance compared to those of the Hanatee variety but had a lower quality of texture hardness than that of the Hanatee variety. At a harvesting period of 12 months, the OMRE60-02-61 line gave a fresh root yield of 2,650 kg/rai, close to the Hanatee. Cassava French fries from the OMRE60-02-61 line had near quality of texture hardness compared to that of the Hanatee variety and had a close score of consumer acceptance compared to those of the Hanatee variety, however, the acceptance of the Hanatee variety was higher. It is recommended that the OMRE60-02-61 line harvested at 8 months be the most appropriate cassava to produce French fries because it has better consumer acceptance than the Hanatee variety.

Symptomatology and Seed Transmission of Columnea latent viroid and Pepper chat fruit viroid in Melon

2023-10-30T15:04:06+07:00

Columnea latent viroid (CLVd) and Pepper chat fruit viroid (PCFVd) are important quarantine pests, causing damage to agricultural products, especially tomato, potato, pepper, and some cucurbits. This work was to study the symptoms and seed transmission of CLVd and PCFVd in melon to provide information for observing abnormal symptoms that might occur in melon growing fields. Melon cultivars were mechanically inoculated at the seedling stage, self-pollinated and seeds harvested for seed transmission investigation. It was found that CLVd and PCFVd could cause disease in melons with 25 – 86 and 0 – 100% infection rates, respectively. All four cultivars of CLVd-infected melon displayed symptoms at 8 weeks post inoculation (wpi) with stunting, shorten internodes, small and stacked leaves, small male flowers with abnormal petals, and abundance of non-developed male and female flowers. While two of three tested cultivars of PCFVd-inoculated melon expressed symptoms at 6 wpi with apical shoot stunting, and fully clustering flowers without of fruit setting. For grow out test in a greenhouse, seed transmission rate of CLVd-infected melon was 0.5% in Melon-2 cultivar only. However, PCFVd seed transmission was not found in all the PCFVd-infected melon cultivars in this study. The current findings of viroid melon diseases could be useful for routine disease observation and immediate eradication of CLVd and PCFVd infected plants to reduce disease dissemination and viroid seed contamination especially in CLVd.

Development of Nitrate Content Prediction Technique of Aloe Vera Leaves using Nondestructive Technique by Near Infrared Spectroscopy

2024-03-25T22:54:52+07:00

This study examined the use of near-infrared spectroscopy to assess nitrate concentration of freshly harvested aloe vera leaves. Equations for predicting nitrate concentration of aloe vera leaves were developed in this work, based on the analysis of 80 samples. The NIR spectra were collected from different positions on the outer rind, specifically the apex, center, and base. Subsequently, the outer layer of the corresponding sites was removed and the concentration of nitrate in the aloe vera gel was examined by nitrate ion meter. The partial least squares regression (PLSR) method was employed to create a prediction equation for the nitrate content. The equation derived from the spectra obtained at the central position demonstrated the highest accuracy, as indicated by a correlation coefficient of prediction of 0.98 and root mean squared error of prediction of 3.50 ppm. The regression coefficients of the nitrate prediction equations were dominated at the wavelengths of 957, 1104 and 1154 nm. Therefore, it is possible to use the NIRS technique to predict the nitrate content of aloe vera leaves without destroying the sample. This technique will allow a quick and accurate measurement of the nitrate content in aloe vera leaves.

Phytochemical Profiles and Antioxidant Activity of Sprouted Mung Bean and Sprouted Sunflower Seeds

2024-01-15T11:56:16+07:00

Mung beans and sunflowers are widely consumed as vegetables during their early stages of germination. Mung bean and sunflower sprouts contain beneficial substances suitable for the development of healthy food products. The purpose of this study was to compare the effects of germination on the phytochemical profiles and antioxidant activity of mung bean (Vigna radiata (L.) Wilczek) cultivar Chainat84-1 and sunflower (Helianthus annuus L.) cultivar Aquara6 hybrid sprouts, as well as to determine the optimal germination period for use as raw materials in the production of nutritious foods. The germinating seeds were evaluated at 0 – 6 days after imbibition (DAI). Moisture content, dry matter, ascorbic acid content, water-soluble protein content, and total phenolic content (TPC) were measured. Antioxidant activities were determined by using 2,2-diphenyl-l-picyrhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. Results showed that sprouting mung bean and sprouting sunflower seeds’ moisture content gradually increased, while dry matter decreased with time. Sprouting mung bean had the highest ascorbic acid content at 1 DAI (1.46 mg/100 g FW), whereas sprouting sunflower seeds had the highest ascorbic acid content at 3 DAI (0.58 mg/100 g FW). Water-soluble protein was highest in sprouting mung bean and sprouting sunflower seeds at 0 DAI of 9.81 and 5.16 mg/g FW, respectively. The highest TPC was found in sprouting mung bean at 4 DAI (46.82 mg GAE/g DW) and sprouting sunflower seeds at 0 DAI (134.70 mg GAE/g DW). Sprouting mung bean had the highest antioxidant activities in the DPPH assay at 4 DAI (IC50 of 2.07 mg/mL) and FRAP at 6 DAI was 2.93 mg GAE/g DW while sprouting sunflower seeds had the highest DPPH assay value at 0 DAI IC50 of 0.19, whereas at 1 and 2 DAI of 0.18 and 0.30 mg/mL, respectively while the highest FRAP value at 0 DAI was 11.62 mg GAE/g DW. The overall results indicated that mung beans and sunflower seeds at 0 DAI had the highest water-soluble protein, suitable for use as raw materials for the protein-based food products. Mung beans at 4 DAI and sunflower seeds at 0 DAI had the highest phenolic compounds and antioxidant activities that are suitable for producing health food products.

Identification of SSR Markers Associated with Northern Corn Leaf Blight Resistance in Sweet Corns

2023-11-03T22:26:17+07:00

Northern corn leaf blight (NCLB) caused by Exserohilum turcicum, is one of the most serious diseases of sweet corn. Resistant variety is often considered the most effective method for controlling NCLB. Conventional breeding for developing sweet corn resistant to NCLB is time-consuming and the evaluation of NCLB resistance in sweet corn is influenced by environmental conditions. Utilising DNA markers to screen for resistance to NCLB in sweet corn is less time consuming and more effective. This research focused on identifying 16 SSR markers that could be associated with polymorphisms related to NCLB disease reaction. Twenty-six commercial sweet corn cultivars/hybrids were used in this study. Results indicated that SSR marker, bnlg182, located on chromosome 1 (bin no. 1.03), exhibited different particular alleles between moderately resistant and moderately susceptible to NCLB disease. Then the bnlg182 marker was used as the template for amplification of the DNA of 158 S₆ lines of sweet corn. The presence of particular alleles related to resistance to NCLB from 10 S₆ lines of sweet corn. These sweet corn lines were planted to evaluate their resistance to NCLB disease. The results indicated that the 10 S₆ lines of sweet corn exhibited a moderate resistance (19 -30%) to NCLB disease. The utilisation of the bnlg182 marker as a screening tool in resistance sweet corn breeding programs offers the advantages of being simple and fast.

Disinfection of Pepper chat fruit viroid in Pepper Seeds

2024-03-25T23:03:23+07:00

Pepper chat fruit viroid (PCFVd) can cause disease in pepper. This disease can be transmitted via seeds and mechanical means. The global pepper seed trade is an important channel for PCFVd dissemination from country to country. The effectiveness of seed disinfection methods for PCFVd ranging from chemical to physical ones was evaluated. The methods using sodium hypochlorite 3%, sodium bicarbonate 10%, hydrochloric acid 0.5 N, trisodium phosphate 10%, hot water and dry heat treatment in combinations at different temperatures and time periods were tested in pepper seed varieties P-74 and P-TV infected with PCFVd 100%. After treatment, the infection rate was inspected by the reverse transcription-polymerase chain reaction technique on the whole seeds, seed coats and seedlings and the germination rates were determined. The results showed that soaking pepper seeds in 50°C hot water for 25 min followed by 72°C dry heat for 24 hours was the best treatment regime. It could get rid of 100% PCFVd while the germination rates remained at 96-99%. This result can be used as a recommendation for seed disinfection for PCFVd.

Mite Pest Species and Their Natural Enemies of the Cannabis Plants

2024-02-12T15:24:46+07:00

Currently, cannabis is allowed to be grown for herbal medicine uses in Thailand. It is becoming a new economic crop with expanding planting area while there is very limited knowledge of the pest species and their distribution. The survey of mite species, the potential pests of cannabis, was carried out from October 2021 to December 2023 in 61 districts of 33 provinces of Thailand. We found 19 species in 7 families of mites and insect, including 15 species of mite pests in 4 families, 2 predatory mites in 1 family, and 1 species of predatory insect. They were: Aculops cannabicola (Farkas) in the family Eriophyidae, Polyphagotarsonemus latus (Banks) in the family Tarsonemidae which caused the tops of cannabis leaves to become small and curled, Brevipalpus californicus group in the family Tenuipalpidae. The other 12 species were in the family Tetranychidae: Eotetranychus suvipakiti Ehara, Neotetranychus sp., Panonychus elongatus Manson, Tetranychus kanzawai Ehara, Tetranychus gloveri Banks, Tetranychus neocaledonicus Andre, Tetranychus piercei McGregor, Tetranychus phaselus Ehara, Tetranychus truncatus Ehara, Tetranychus sp., Tetranychus urticae Koch and Tetranychus hydrangeae Pritchard & Baker. Spider mites were found to cause damage to the lower leaves of cannabis, turning them yellow and eventually dry. The most important mite species of cannabis was T. truncates which was found infesting cannabis in almost every area surveyed. In addition, 2 species of predatory mites and 1 predatory insect were found in this study: Amblyseius cinctus Corpuz-Raros & Rimando, Neoseiulus longispinosus (Evans), and Scolothrips asura Ramakrishna & Margabhandu.

Development of Tetra-primer ARMS-PCR for Selection and Discrimination of CMD-Resistant Cassava Varieties Used in Thailand

2024-02-23T10:19:15+07:00

Cassava mosaic disease (CMD) is a major disease that causes damage to cassava production worldwide. CMD-resistant cassava varieties obtained from the International Center for Tropical Agriculture (CIAT) and the International Institute of Tropical Agriculture (IITA), including 7 varieties, namely TME 3, C 33, IITA-TMS-IBA 920057, IITA-TMS-IBA 972205, IITA-TMS-IBA 980505, IITA-TMS-IBA 980581 and TME B 419, are currently being used as parent lines to create hybrids resistant to CMD suitable for cultivation in Thailand. The tetra-primer ARMS-PCR is a technique for single-nucleotide polymorphism (SNP) detection. It has the advantages of amplifying multiple alleles in a single reaction with the inclusion of a control fragment, cost-effectiveness as well as simplicity in operation. The purposes of this research were to develop primer sets using the tetra-primer ARMS-PCR technique to detect SNP markers associated with CMD resistance for the selection of resistant varieties and to develop a primer set for discrimination of variety within 7 CMD-resistant varieties being used in Thailand. The resultant primer sets have been readily developed and optimized condition to detect SNP markers Ex2-78, Ex2-157, Ex3-128, and S12_7926132 on chromosome 12, and can be used to select CMD-resistant varieties. For discrimination of CMD-resistant varieties, a primer set was developed to detect the SNP marker S12_8910428 in the DNA polymerase δ subunit 1 gene, and could distinguish TME B 419 from the remaining six resistant varieties. To our knowledge, this is the first report of using tetra-primer ARMS-PCR, which is cost-effective and simple to operate, in SNP detection for CMD-resistance selection in cassava.