• Search Research Projects
  • Search Researchers
  • How to Use
  1. Back to project page

2004 Fiscal Year Final Research Report Summary

Mechanism and Inheritance of Continuous Light-Tolerance in Cucurbita moschata

Research Project

Project/Area Number 15580023
Research Category

Grant-in-Aid for Scientific Research (C)

Allocation TypeSingle-year Grants
Section一般
Research Field Horticulture/Landscape architecture
Research InstitutionOKAYAMA UNIVERSITY

Principal Investigator

MURAKAMI Kenji  Okayama University, The Graduate School of Natural Science and Technology, Lecturer, 大学院・自然科学研究科, 講師 (40200266)

Co-Investigator(Kenkyū-buntansha) MASUDA Masaharu  Okayama University, Faculty of Agriculture, Professor, 農学部, 教授 (90026617)
Project Period (FY) 2003 – 2004
Keywordsantioxidant enzyme / chlrosis / continuous light-injury / expanding leaves / mature leaves
Research Abstract

In many species, plants show injury symptoms such as chlorosis under continuous light. On the other hand, some species do not show any injury and grow well even under continuous light. In this study, we examined the mechanisms and inheritance of continuous light-tolerance using tolerant and sensitive cultivar in Cucurbita moschata.
Reciprocal crosses were conducted for tolerant and sensitive cultivar. In the reciprocal F_1, the degree of chlorosis expressed as chlorophyll concentration was mid-parent value. The chlorophyll concentration of F_2 from tolerant × sensitive cultivar ranged from tolerant value to sensitive value and there was no distinct segregation. In the F_3 progeny from a sensitive F_2 plant, one sensitive and one tolerant group were segregated in approximately 9:1 ratio. These results suggested that continuous-light tolerance was controlled by two or more alleles involving recessive genes.
Continuous light-injury occurred only on young, expanding leaves. We hypothesized that mature leaves sense continuous light, and this information induces the injury of new leaves. To examine this hypothesis, we covered plants partially. Injury did not occur on expanding leaves under continuous light when mature leaves were covered for 12 hr/day. Continuous light-injury did not occur on the expanding leaves of sensitive scion grafted to tolerant rootstock with mature leaves. These results indicated that the expanded leaf of sensitive cultivar produced some injury-inducer under continuous light.
The activities of superoxide dismutase and catalase in continuous light-tolerant cultivar increased more rapidly than those in sensitive cultivar. These results suggested that a rapid increase in the antioxidant enzymatic activities was involved in the mechanism of tolerance to continuous light.

URL: 

Published: 2006-07-11  

Information User Guide FAQ News Terms of Use Attribution of KAKENHI

Powered by NII kakenhi