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Tomato (Solanum lycopersicum) is the most important vegetable and fruit crop in the family Solanaceae worldwide. Numerous pests and pathogens, especially viruses, severely affect tomato production, causing immeasurable market losses. In Taiwan, the cultivation of tomato crops is mainly threatened by insect-borne viruses, among which pepper veinal mottle virus (PVMV) is one of the most prevalent. PVMV is a member of the genus Potyvirus of the family Potyviridae and is non-persistently transmitted by aphids. Its infection significantly reduces tomato fruit yield and quality. So far, no PVMV-resistant tomato lines are available. In this study, we performed nitrite-induced mutagenesis of the PVMV tomato isolate Tn to generate attenuated PVMV mutants. PVMV Tn causes necrotic lesions in Chenopodium quinoa leaves and severe mosaic and wilting in Nicotiana benthamiana plants. After nitrite treatment, three attenuated PVMV mutants, m4-8, m10-1, and m10-11, were selected while inducing milder responses to C. quinoa and N. benthamiana with lower accumulation in tomato plants. In greenhouse tests, the three mutants showed different degrees of cross-protection against wild-type PVMV Tn. m4-8 showed the highest protective efficacy against PVMV Tn in N. benthamiana and tomato plants, 100% and 97.9%, respectively. A whole-genome sequence comparison of PVMV Tn and m4-8 revealed that 20 nucleotide substitutions occurred in the m4-8 genome, resulting in 18 amino acid changes. Our results suggest that m4-8 has excellent potential to protect tomato crops from PVMV. The application of m4-8 in protecting other Solanaceae crops, such as peppers, will be studied in the future. [ABSTRACT FROM AUTHOR]

The National Digital Library of Theses and Dissertations and the NCL (National Central Library) Taiwan Periodical Literature database were used to analyze dissertations and journal articles on early childhood life education. The researcher explored the research themes of life education for young children aged 3 to 6 years in Taiwan and offered strategies for improving learning in early childhood life education. Eight categories of themes were examined. In addition, the curriculum development of learning in early childhood life education was identified: (1) life event core curriculum, (2) sympathy core curriculum, (3) example core curriculum, and (4) anima core curriculum. Several teaching approaches of learning in early childhood life education are proposed: (1) teaching through picture books, (2) learning through experience, (3) teaching through instructional media, (4) teaching through concept mapping, (5) teaching through stories, and (6) teaching through parent–teacher collaboration. Developing and implementing the strategies of learning in early childhood life education is crucial for cultivating psychological wellbeing in young children and improving the quality of Taiwan's early childhood education system. [ABSTRACT FROM AUTHOR]