Effects of MNU Mutation on Productivity, Grain Quality and Allelopathic Potential of Rice

概要

Doctoral Dissertation
Effects of MNU Mutation on Productivity, Grain Quality and Allelopathic
Potential of Rice

KIFAYATULLAH KAKAR

Graduate School for International Development and Cooperation
Hiroshima University

March 2021

Effects of MNU Mutation on Productivity, Grain Quality and Allelopathic
Potential of Rice

D182350
KIFAYATULLAH KAKAR

A Dissertation Submitted to
the Graduate School for International Development and Cooperation
of Hiroshima University in Partial Fulfillment
of the Requirement for the Degree of
Doctor of Agriculture
March 2021

_________________________________________________________________________________________________

Table of Contents
Approval letter ………………………………………………………………………….. i
Table of contents ………………………………………………………………….......... ii
List of Figures …………………………………………………………………………... v
List of Tables .……………………………………………………………………........... vi
List of Appendixes ……………………………………………………………………... vii
List of Abbreviations …………………………………………………………….......... viii
Acknowledgements …………………………………………………………………….. xi
Dedication …………………………………………………………………………........ xii
Summary of Dissertation ……….……………………………………………………... xiii
Chapter 1 …………………………………………………………………………..…...… 1
General Introduction ……………………………………………………………………. 1
Abstract ……………………………………………………………..………………....…. 1
1. Methods of Rice Improvement ……………………………………………………… 1
2. Mutation Technology ……………………………………………………………...… 3
3. Type of Mutations ..…………………………………………………………..…..….. 4
3.1. Physical mutation ………………………………………………………………… 4
3.2. Chemical mutation ……………………………………………………………….. 4
3.3. Biological mutation ……………………………………………………….…….... 4
4. MNU Mutation ………………………………………………………………...….…. 5
4.1. MNU Mutation and Rice Productivity …………………………………….…..…. 6
4.2. MNU Mutation and Rice Grain Quality ………………………………………….. 7
4.3. MNU Mutation and Rice Allelopathy ………………………………….….…..…. 8
5. Research Objectives ……………………………………………………………...….. 8
6. Scientific Contribution of the Research …..………………………………………... 9
7. Structure of Thesis Dissertation …………………………………………….………. 9
Chapter 2 ……………………………………………………………………………....... 10
Efficacy of N-methyl-N-nitrosourea (MNU) Mutation on Enhancing the Yield and
Quality of Rice …...…………………………………………………..……….…..…....... 10
Abstract ……………………………………………………………………………..…... 10
1. Introduction ………………………………………………………………………… 10
2. Materials and Methods …………………………………………………………….. 12
2.1. Experimental Site and Design …………………………………………….…….. 12
2.2. Plant Materials and Seedling Management ……..………………………….…… 13
2.3. Measurements of Growth and Yield Attributes …………………...……….…… 13
2.4. Measurements of Physicochemical Properties ………………………………...... 14
2.5. Statistical Analysis …………………………………………………………….... 14
3. Results ……………………………………………………………..………………… 14
3.1. Growth Attributes ………………………………………………..……………… 14
3.2. Grain Yield and its Components …………………..……………..……...……… 15
3.3. Physicochemical Properties and Appearance …………………….……………... 17
ii

_________________________________________________________________________________________________

3.4. Relationship of Grain Yield with other Parameters ………………………..….... 19
4. Discussion ……………………………………………….…………...…………….... 25
5. Conclusion …………………………………………….……………..……………… 28
Chapter 3 ………………………………………………………………...……………… 29
Efficacy of N-methyl-N-nitrosourea Mutation on Physicochemical Properties,
Phytochemicals, and Momilactones A and B in Rice …………….……..….……….... 29
Abstract ………………………………………………………………………..………... 29
1. Introduction ……………………………………………………………..….………. 29
2. Materials and Methods ……………………………………………………...……... 31
2.1. Experimental Design and Plant Materials ………….…………………..……….. 31
2.2. Measurement of Physicochemical Properties ………………..………...……….. 32
2.3. Standards and Reagents ……………………………………….………………… 32
2.4. Extraction and Samples Preparation ……..…………………………...……….... 32
2.5. Antioxidant Assays …………………………………………………...………… 33
2.5.1. DPPH Scavenging Assay ……………………………………...………… 33
2.5.2. ABTS Cation Discoloration Assay ………………………………………. 34
2.6. Determination of Total Phenolic Contents ……………………………………… 34
2.7. Determination of Total Flavonoid Contents …...………………………...……... 34
2.8. Quantification of Momilactones A and B ………..……………………………... 34
2.9. Statistical Analysis ……………………………………………………………… 35
3. Results ……………………………………………………………………………….. 35
3.1. Antioxidant Activities …………………………………………………...……… 35
3.2. Total Phenolic and Flavonoid Contents …….……………………………....…... 36
3.3. Momilactones A and B …...………………………………………………….….. 37
3.4. Correlation of Biological Contents of Rice Grain …………………………….… 44
3.5. Principal Component Analysis …...………………………………………….…. 44
4. Discussion ………………………………………………………………………....… 47
5. Conclusions ……………………………………………………………………...….. 49
Chapter 4 ………………………………..………………………………...…………….. 51
Evaluation of MNU Mutation on the Relation between Allelopathic Potential and
Grain Quality of Rice Plant ..………………………………….……………………….. 51
Abstract ………………………………………………………...………………..……… 51
1. Introduction ……………………………………………………………...……….… 52
2. Materials and Methods …………….………………………………………………. 55
2.1. Plant Materials and Experimental Design ………………………………………. 55
2.2. Reagents and Standards ………………………………………………………… 55
2.3. Extraction and Sample Preparation …..……………………………………….… 55
2.4. Antioxidant Assays …………………………………………...……………..….. 55
2.5. Determination of TPC and TFC ………………………………...…………….… 56
2.6. Quantification of Momilactones A and B ……..…………………...………….... 57
2.7. Allelopathy Activities ………………………………………………...……….... 57
2.8. Identification of Phenolic Compounds by HPLC ……………………...…….…. 58
iii

_________________________________________________________________________________________________

2.9. Statistical Analysis …………………………………………...………………..... 59
3. Results ………………………………………………………………………….……. 59
3.1. Inhibitory Activity of Extracts ……………………………………...…….…….. 59
3.2. Identification of Phenolic Compounds …………………………………….……. 63
3.3. Correlation of Grain Quality with Allelopathic Activity ……………...….…….. 63
4. Discussion …………………………………………………………………...….…… 68
5. Conclusion …………………………………………………………………...….…... 71
Chapter 5 ………………………………………………………………………………... 72
General Discussions and Conclusions …………………………………...……………. 72
1. Rice Productivity …………………………..……………………………...…….….. 72
2. Rice Grain Quality ……………………………………………………...…….......... 74
3. Rice Plant Biological Activity ……...…………………………………...………….. 76
4. Rice Plant Allelopathy ……………………………………………………………… 79
References ………………………………………………………………………………. 82
Appendixes ……………………………………………………………...….………….. 100

iv

_________________________________________________________________________________________________

List of Figures
Figure 1.

Chemical structure of MNU mutagenesis …………………………..…….. 6

Figure 2.

Description of nursery establishment and field management …………… 13

Figure 3.

The appearance quality of cultivars and mutant lines ………………..….. 17

Figure 4.

The correlation of grain yield with panicle number, spikelet number,
ripened ratio, and 1000 grain weight ………….…………………...…….. 21

Figure 5.

The correlation of grain yield with amylose, protein, and lipid contents, and
taste score ………………………………...…………………………...…. 23

Figure 6.

Description of the extraction method of the samples ………………….… 33

Figure 7.

Contents of MA in rice grain, husk, and straw of the original cultivars and
mutant lines …………………………………………...……………….… 39

Figure 8.

Contents of MB in rice grain, husk, and straw of the original cultivars and
mutant lines ………………………………………………………...….… 41

Figure 9.

Chemical structure of momilactones A and B ………………………….... 41

Figure 10.

Extracted ion chromatograms (EIC) and mass spectra (MS) of
momilactones A and B in the rice straw sample of K1 ………………..… 42

Figure 11.

Extracted ion chromatograms (EIC) and mass spectra (MS) of
momilactones A and B in the rice straw sample of K2 ………………..… 43

Figure 12.

Principal component analysis of grain yield with physicochemical
properties and biological activities …………………………...……….…. 46

Figure 13.

General experimental design of the allelopathic assay …………...……... 58

Figure 14.

The IC50 value for inhibitory activity of rice husk and straw on the
germination of lettuce ………………………………………………….… 60

Figure 15.

The IC50 value for inhibitory activity of rice husk and straw on the
germination of barnyard grass …………………………………………… 60

Figure 16.

The IC50 value for inhibitory activity of rice husk and straw on shoot and
root length of lettuce ……………………………………………………... 61

Figure 17.

The IC50 value for inhibitory activity of rice husk and straw on shoot and
root length of barnyard grass ……………………………...……………... 61

v

_________________________________________________________________________________________________

List of Tables
Table 1.

Origin and description of the selected rice cultivars and mutant lines ...… 12

Table 2.

Description of growth parameters between cultivars and mutant lines ….. 15

Table 3.

Description of grain yield and its components between cultivars and mutant
lines ………………………………………………………...………...….. 16

Table 4.

Description of physicochemical properties of rice grain between cultivars
and mutant lines ………………………………………………………….. 18

Table 5.

The correlation coefficient of grain yield with growth parameters, yield
components, and physicochemical properties between cultivars and mutant
lines ………………………………………………………...…………..... 24

Table 6.

Classification of grain length and shape of milled rice ……..………….... 26

Table 7.

Antioxidant activities, total phenolic and total flavonoid contents of the rice
grain, husk, and straw in mutant lines and original cultivars …..…..……. 37

Table 8.

The correlation coefficient of grain yield and physicochemical properties
with phytochemical contents and momilactones of rice grain ………...… 45

Table 9.

The IC50 value for inhibitory activity of rice husk and straw on the
germination rate and growth parameters of selected plants …...…….…... 62

Table 10. ...

この論文で使われている画像