Program Overview

Introduction to the Applied Plant Science Course: Horticultural Plant Breeding

The Applied Plant Science Course, with a focus on Horticultural Plant Breeding, is led by Professor Tsuyoshi Yasuda and Associate Professor Ryuhei Fujimoto. This course delves into the mechanisms of reproduction and breeding in horticultural plants, aiming to contribute to variety improvement, seed production, and fruit production through education and research.

Research Areas

The main research themes currently include:

• (1) Research on Self-Incompatibility in Pear Trees
  • This research explores the self-incompatibility mechanism in pear trees, which is genetically controlled by a single locus. The interaction between the pistil and pollen is crucial, with the same haplotype leading to incompatibility and the cessation of pollen tube growth.
  • Molecular biological and cytological approaches are used to elucidate the mechanism of self-incompatibility.
• (2) Research on Heterosis in Brassica Vegetables
  • Heterosis, or hybrid vigor, is a phenomenon where hybrids exhibit superior traits compared to their parents. This research focuses on understanding the molecular mechanisms behind heterosis in Brassica vegetables, such as Chinese cabbage and cabbage.
  • The goal is to identify genes related to heterosis and understand how they contribute to increased yield and improved traits in F1 hybrids.

Detailed Research

(1) Self-Incompatibility in Pear Trees

• The self-incompatibility reaction between the pistil and pollen is due to the interaction between the S-RNase gene in the pistil and the SLF (S-locus F-box) gene product in the pollen.
• Research involves creating a BAC library of pear and using chromosome walking to construct a BAC contig around the S-locus. This has led to the identification of a group of F-box protein genes called SFBB, which may be involved in recognizing and degrading non-self S-RNase.

(2) Heterosis in Brassica Vegetables

• To elucidate the molecular mechanism of heterosis, transcriptome analysis is conducted to compare the expression of genes in F1 hybrids and their parents.
• QTL analysis is also performed to identify regions and genes associated with heterosis.
• Additionally, the role of epigenetic regulation in heterosis is being investigated, as it is suggested that epigenetic modifications may contribute to the phenomenon of heterosis.

Conclusion

The Applied Plant Science Course, with its focus on Horticultural Plant Breeding, offers a comprehensive approach to understanding the mechanisms of plant reproduction and breeding. Through research and education, the course aims to contribute to the improvement of crop varieties and the development of more efficient breeding techniques, ultimately enhancing fruit and seed production.