Thai Journal of Science and Technology

Genetic Relationship Assessment of Apples Using HAT-RAPD Technique

Narumol Thanananta — 2024-01-18

High annealing temperature-random amplified polymorphic DNA (HAT-RAPD) technique was used for genetic relationship assessment of 14 apple samples that sold in Thailand. Thirty-one random primers out of seventy-two were successful for DNA amplification. Then 20 random primers which gave clear amplified products were selected for DNA fingerprinting. The result showed significant differences among 14 samples and also showed some bands in each sample. Moreover, this research found 3 random primers which tended to be DNA markers for apple identification. A dendrogram constructed based on polymorphic bands showed genetic similarities among apples and separated them into 3 clusters with similarity coefficients ranging from 0.57 to 0.86.

Effect of Temperature and Packaging on Quality of Pigeon Pea Seeds (Cajanus cajan L.) During Storage

Mayura Lanchai — 2024-03-05

Pigeon pea (Cajanus cajan L.) is a native legume crop with high protein content. It is the main ingredient in a traditional dish in Tak province. A method to maintain the quality of pigeon pea seeds during long-term storage for seed saving and food processing as raw materials were developed. Pigeon pea seeds were stored at 13 and 30 ^oC using different packaging types including PE (polyethylene) bags, PEA (polyethylene base active) bags and PA/PE (vacuum; polyamide & polyethylene) bags. Seed quality is determined by several factors like seed germination, seed moisture content, seed weight, O₂ and CO₂ in packaging, insect infestation, seed color (L* C* h^o) and seed protein content. Results showed that storing at 13 ^oC can maintain better quality than storing at 30 ^oC in all types of packaging, especially storing in PA/PE bags during 12 months of storage, the seed germination rate was high and low insect infestation. This method can be adopted by farmers to extend the shelf life of their pigeon pea seeds.

Genetic Relationship Assessment of Vanda Using HAT-RAPD Technique

Narumol Thanananta — 2024-03-12

The Vanda is the second most important commercial orchid after the Dendrobium. There are many species and hybrids, making it difficult to classify by morphology and easily confused. High annealing temperature-random amplified polymorphic DNA (HAT-RAPD) technique was used to identify 12 samples of Vanda. The total 72 random primer were screened and 30 primers could be used for DNA amplification. 18 primers were selected and used to analyze all the DNA samples. Total 211 bands were detected, of which 206 were gave different DNA fingerprinting and all cultivars were clearly differentiated by using 14 primers. A dendrogram constructed based on polymorphic bands showed genetic similarities among Vanda each cultivar with similarity coefficients ranging 0.37-0.69. The HAT-RAPD markers developed can be used to identify Vanda cultivar and plan to breeding program.

Comparison of Morphological and Anatomical Characteristics of Rice Paddy Herb (Limnophila aromatica Merr), Brahmi (Bacopa monnieri (L.) Wettst) and Giant Bacopa (Bacopa caroliniana (Walt) Robins)

Mattanaporn Maikami — 2024-03-26

Identification of local vegetables and herbs using only morphological characteristics do not probably sufficient. It must rely on studies in other fields. Plant anatomy is another tool that efficient support to classify plant species. Rice paddy herb, brahmi and giant bacopa are plants in the same family and habitat. It is probably confused with taking advantage of these plants. Rice paddy herb, brahmi and giant bacopa were studied the morphology of stems, leaves, and flowers using a stereo microscope. Additionally, they were studied the anatomy of leaf surface and stem tissues using a light microscope to compare and classify these plant species. When considering stems and leaves covered with trichome can be classified, the brahmi stem is glabrous. And then, leaf shape is able to classify rice paddy herb and giant bacopa apart. In view of flower, the sepal characteristic is capable of separating rice paddy herb from the other 2 species. And subsequently, brahmi and giant bacopa can be identified by the color at the base of the petals. In the case of anatomical characteristics, the layer of air space divided giant bacopa from rice paddy herb and brahmi. After that collenchyma tissue of the stem was applied to sort between rice paddy herb and brahmi. Rice paddy herb obviously demonstrates collenchyma tissue. Morphological and/or anatomical characteristics are able to classify rice paddy herb, brahmi and giant bacopa. Additionally, these knowledges expand the limited anatomical information on this plant group, application to other related study fields as well as leading to the development and conservation of plant genetic resources for further efficiency.

A Plant Simulation Approach Applied Sequencing Strategies for Buffer Prediction: A Case Study in an Automotive Assembly Line

Anan Butrat — 2024-03-26

In this study, a plant simulation approach to buffer prediction for an automotive assembly line was proposed. Currently, the assembly line has exceeded the buffer size. The idea to reduce buffer size is to increase worker size and sequencing strategy. With simulation, two approaches, including throughput analysis and production time analysis, are proposed. The throughput analysis can find the required buffer sizes for maximizing throughput when the total available time is used. The production time analysis can determine the time spent using each buffer space with a fixed throughput size.
In terms of results, the sequencing strategy that produces two normal models and one new model provides the first plan to implement. Without increasing worker size, this strategy can finish 48 cars per shift by using 8 buffer spaces. Moreover, increasing one worker is the second plan so that
the throughput of this strategy can reach 58 cars per shift. Additionally, this simulation model highlights the modified Blocking After Station (MBAS) that can define not only buffer usage but also the buffer requirement. This research offers a simulation approach to the prediction of buffet usage and the requirement to define an action plan for an unfamiliar task in the automotive assembly line.