Abstract

Purpose

Rice is the predominant crop of Tamil Nadu state, India that occupies about 30% of the total cropped area. However, grain type and quality are the critical traits that determine the market value and domestic consumption rice variety. Most of the households of Tamil Nadu, India prefer to consume medium slender to fine grain type of rice. Hence, the present study was conducted to induce medium slender grain type in popular rice variety ADT 37 (Aduthurai 37), a short bold rice variety using gamma rays (GR) and electron beam (EB) mutagens.

Materials and methods

Healthy, dried seeds (12.0% moisture content) of ADT 37 rice variety were exposed to various doses of GR (100–500 Gy) and EB (200–600 Gy). The irradiated population were maintained up to M₄ generation by plant to progeny row basis to identify stable mutants for grain-type variation. The selected grain-type mutants (medium slender- and slender-type mutants) in M₄ generation were characterized for phenotypic and grain quality traits.

Results

A high frequency of desirable grain-type variation was observed in EB-irradiated population than gamma-irradiated population. A total of 25 grain-type mutants (long slender and medium slender) were obtained in M₄ generation of ADT 37 variety. The morphological characterization and cooking quality assessment of the ‘grain-type’ mutants revealed that six out of 25 mutants viz., M-3 (Mutant-3), M-5, M-9, M-10, M-13 and M-15 recorded single plant yield of more than 30 g. There was non-significant variation in yield per plant (g) among the mutants and control (parent) due to key changes in grain type and thousand grain weight.

Conclusion

EB showed higher mutation frequency, mutagenic effectiveness and efficiency than the GR in inducing both chlorophyll and viable mutants. This study revealed that the percentage contribution of the EB was 2.57 times higher than that of GR in obtaining desirable slender and medium slender grain-type mutants. The grain-type mutants obtained in the present study can be either directly released as variety or used as parents in hybridization program of rice crop improvement.

中文翻译：

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电子束相对于伽马射线在水稻 (Oryza sativa L.) 中诱导所需粒型突变的效率

 抽象的

 目的

水稻是印度泰米尔纳德邦的主要农作物，约占总种植面积的30%。然而，谷物类型和品质是决定市场价值和国内消费大米品种的关键性状。印度泰米尔纳德邦的大多数家庭更喜欢消费中细粒到细粒的大米。因此，本研究旨在利用伽马射线（GR）和电子束（EB）诱变剂在流行的水稻品种ADT 37（Aduthurai 37）中诱导中细粒型，ADT 37是一种短粗粒型水稻品种。

 材料和方法

将 ADT 37 水稻品种的健康干燥种子（含水量 12.0%）暴露于不同剂量的 GR（100-500 Gy）和 EB（200-600 Gy）。受辐射的种群以植物到子代行为基础维持至M ₄代，以鉴定谷物类型变异的稳定突变体。对M ₄代中选定的籽粒型突变体（中细长型和细长型突变体）进行了表型和籽粒品质性状的表征。

 结果

与伽马射线照射群体相比，在 EB 照射群体中观察到所需谷物类型变异的频率较高。 ADT 37品种M ₄代共获得25个粒型突变体（长细长型和中细长型）。 “谷物型”突变体的形态特征和烹饪质量评估表明，25 个突变体中有 6 个，即 M-3 (Mutant-3)、M-5、M-9、M-10、M-13 和M-15单株产量超过30克。由于籽粒类型和千粒重的关键变化，突变体和对照（亲本）之间的单株产量（g）没有显着变化。

 结论

EB 在诱导叶绿素和活突变体方面表现出比 GR 更高的突变频率、诱变效果和效率。本研究表明，在获得理想的细细粒型和中细细粒型突变体方面，EB的贡献率是GR的2.57倍。本研究获得的粒型突变体既可以直接作为品种发布，也可以作为亲本用于水稻作物改良杂交计划。