Efficacy of N-methyl-N-nitrosourea (MNU) Mutation on Enhancing the Yield and Quality of Rice

Kifayatullah Kakar,Tran Dang Khanh,Imran Khan Wafa,Tran Dang Xuan,Tran Dang Dat,Hoang-Dung Tran,Nguyen Van Quan

doi:10.3390/agriculture9100212

Abstract

Mutation technology has been applied more in recent decades to achieve novel products that are not commonly found in nature. An experiment was conducted to examine the effects of an N-methyl-N-nitrosourea (MNU) mutation on the growth, yield, and physicochemical properties of rice. Seeds of two rice cultivars (K1: DT84, and K3: Q5), along with their mutant lines (K2: mutated DT84, and K4: mutated Q5), were sown, and the established seedlings were transplanted to an open field. Ten hills per plot were randomly selected to evaluate growth parameters, yield, and components. Physicochemical attributes, including protein, amylose, and lipid contents, as well as taste score were measured by a quality tester device. The results showed that plant length, tiller number, and panicle length were higher in mutant lines than those of their cultivars. Furthermore, mutant lines took longer to reach heading and maturity stage. The highest panicle number, spikelet number, repined ratio, 1000 grain weight, 1000 brown rice weight, and grain yield were obtained in mutant lines, as compared to cultivars. The greatest grain yield was obtained in the K4 mutant line (11.6 t/ha), while the lowest was recorded in the K1 cultivar (7.7 t/ha). Lower amylose, protein, and lipid contents were observed in mutant lines compared to those in cultivars. The taste score, which increased from 67.7 to 73.7, was found to be correlated with lower amylose, protein, and lipid contents. The mutation approach increased the grain length but decreased the grain width of tested varieties. This study highlights and suggests the importance of MNU mutation in terms of rice yield improvement with preferable quality.

Highlights

Rice (Oryza sativa L.) is one of the leading crops and provides the main source of calories for more than half of the world’s population [1,2,3]
Anh et al [5] explained that full-grain weight is the key decider for grain yield; results of this study showed that all the yield components were responsible for grain yield production in both cultivars and mutant lines
Grain yield has a linear correlation with its components [31]; we found a linear correlation between grain yield and its components, which is in line with the previous study

Summary

Introduction

Rice (Oryza sativa L.) is one of the leading crops and provides the main source of calories for more than half of the world’s population [1,2,3]. An increasing population has raised demands for rice production worldwide, especially in Asian countries where rice is consumed as part of the typical diet [4,5]. Various methods and techniques of genetic manipulation have. Agriculture 2019, 9, 212 been applied to optimize rice production, such as mass selection, hybridization, mutation, and genetic modification, among others [6]. Utilization of gamma rays has recently raised attention as a speedy method to improve the qualitative and quantitative properties for several crops [8]. El-Degwy [9] stated that gamma irradiation increased heading time, plant length, and panicle number per plant, but it decreased total grain yield compared to those of nonmutagenic rice plants. Induced mutation is a promising tool for creating new genotypes, changing major genes, and governing the quantitative character [10]

Methods

Results

Discussion

Conclusion