Performance of Putative Mutants and Genetic Parameters of Plectranthus amboinicus (L.) through Mutation Induction With Colchicine

Genetic enhancement in vegetatively propagated crops can be done through mutation induction. Colchicine-induced mutation is one of the methods that can be employed to increase plant genetic diversity. This study aimed to determine the effect of colchicine on the performance and genetic parameters of MV3 generation of Plectranthus amboinicus (L.). This study was conducted at the Laboratory of Agricultural Seed Management, Plantation Research and Development Center, from June 2018 to June 2019. Nodes and shoots were used as explants. Mutation induction was performed using colchicine at concentrations of 0%, 0.02%, 0.04%, and 0.06%. Explant regeneration and subculture were done on MS0 medium. The number of plantlets yielded were 59 (0% concentration of colchicine), 60 (0.02%), 81 (0.04%), and 80 plantlets (0.06%), respectively. Results indicated that colchicine-induced mutation in an in vitro culture was able to generate high genetic diversity in both quantitative and qualitative characters of the plantlets. At the concentration of 0.04%, colchicine produced the highest frequency of putative mutants (28.4%). Genetic parameters in MV3 generation of P. amboinicus plantlets showed that five quantitative characters, i.e. plantlet height, number of leaves, number of shoots, leaf length, and number of roots had high heritability values at a concentration around the LC50 value (0.0275%).

Radiosensitivity of rice varieties of Mira-1 and Bestari mutants using gamma rays irradiation

New rice varieties could be released by various plant breeding methods including mutation induction using gamma rays irradiation. Radiosensitivity and LD50 values (Lethal Dose, 50%) can be determined from the morphological response of plants to irradiation treatment in M1 generation. The research aims to determine the value of LD50 and the performance of rice mutant traits of Mira-1 and Bestari. The experiment was conducted using the Randomized Complete Block Design (RCBD) with two factors (rice varieties and gamma irradiation doses) and three replications. The plant traits observed were the percentage of germination, seedling height, and root length in the seedling phase. The results showed that LD50 values in the Mira-1 and Bestari varieties differed in all observed characters. The optimum dose to induce rice mutation of the varieties under investigation is within the range of 521.40 – 663.68 Gy.

Mutation induction in the pineapple (Ananas comosus L. Merr) using colchicine

Pineapple is a tropical fruit that has high economic value. Mutation is a method to increase plant diversity which plays an essential role in plant improvement. This study aimed to induce mutations in pineapple using colchicine. This study was arranged in a factorial completely randomized design. The first factor was pineapple genotypes (i.e., Gemilang, Bangka, Queen, and Suska Kualu) and the second factor was colchicine concentration (i.e., 0.03%, 0.04%, 0.05%, and control). There were 16 treatments with five repetitions so the total was 80 experimental units. Observations were made for three months after treatment in the vegetative phase. Observation parameters included leaf shape, leaf color, plant height, number of leaves, leaf width, and length of stomata. This study indicated that the interaction between genotype and colchicine significantly differed in plant height and the number of leaves. Colchicine significantly increased the length of stomata, and genotype significantly affected all observed parameters. This study concluded that 0.05% colchicine significantly increased plant height (26.67%) and the number of leaves (48.98%) in the Gemilang genotype but decreased plant height and leaf number in other genotypes. This study suggests the need for observation of the flowering phase and fruit quality due to colchicine treatment.

Evaluation Of The Mutagenic Potential Of The Polyphenol Extract From Blueberries In The Ames Test

In this research, mutagenic properties of blueberry polyphenol extract were studied in gene mutation induction test (Ames test) on four strains of Salmonella typhimurium TA98, TA100, TA1535, TA1537. None of the strains of Salmonella typhimurium showed statistically reliable dose-dependent increase in number of revertant colonies in the presence of investigated drug in the studied dose range from 4,0 to 40,0 mg/ml relative to baseline of spontaneous mutations. The blueberry extract does not have any mutagenic activity in the researched dose range in relation to TA98, TA100, TA1535, TA1537 strains of Salmonella typhimurium.

Mutation Breeding in Ornamentals

The promising possibilities of mutation breeding in ornamental plants have led to a great interest in effective mutagenic treatment protocols for various species. This review discusses mutagenic treatments of a large number of ornamental genera, the advantages and disadvantages of various techniques, and the possibilities of improving the associated protocols. A number of nontargeted mutagenesis methods are available, ranging from chemical treatment with alkylating agents to irradiation with X-rays, gamma rays, and neutron or heavy ion beams at various doses. These are all relatively inexpensive and have been proven to be effective mutagens in a large number of diverse species. Genetic engineering, however, remains mostly impractical for many ornamental breeding operations because of the high cost and lack of knowledge necessary to successfully transform and regenerate ornamental crops. Of the available nontargeted mutagens, irradiation with gamma rays is still the most popular. It provides high consistency compared with chemical mutagens, albeit at a seemingly lower mutagenic efficiency. Changes in the radiation dose rate may increase the efficiency, although chronic irradiation over a longer period causes fewer deleterious mutations than the commonly used acute irradiation protocols. Heavy ion beam irradiation may also provide highly consistent mutation induction at higher efficiencies because of the high particle energy associated with these treatments. There are also opportunities to improve chemical mutagenesis. Although the required knowledge of specific gene functions in many ornamentals is still lacking, combination mutagenesis with ethyl methanesulfontate with genetic screening in a process known as TILLING (Targeting Induced Local Lesions IN Genomes) may lead to a powerful mutation breeding tool in the future. Mutation breeding is still very useful, and many opportunities are available to improve the existing methods.

CROP ADAPTATION TO CLIMATE CHANGE: High-Temperature Stress in Drought-Prone Areas

The papers presented in this special issue are focused on the development of mutant lines and new crop varieties of rice and common bean with improved adaptation to climate change. Also included are the development or adaptation of screening techniques that enable efficient selection of desired phenotypes in plant breeding programmes. The breeding methods used are based on mutation induction and mutation detection, where mutation induction is via physical mutagenesis using gamma and X-ray irradiation. Selection for improved mutant lines is achieved through screening for plant performance in the laboratory, green house and field under hight temperature and/or drought stress. The papers presented are the result of a 5-year coordinated research project (CRP) on Climate Proofing Crops: Genetic Improvement for Adaptation to High Temperatures in Drought Prone Areas and Beyond, funded by the IAEA. The CRP, initiated in 2011, focused on tolerance to increased temperatures in rice and common bean. All participating countries generated new mutant populations in rice and bean and identified heat-tolerant lines with better yields than local standard varieties

Evaluation of Proximate and Mineral Composition of Mutant Dolichos Lablab (Lablab purpureus L.) Accessions in Kenya

Plant breeding through induced mutation technology is a potent method to creating new variants of food crops with of desirable phenotypic, genetic and biochemical functions. It is a catalyst in developing improved crop varieties where classical hybridization or selection have limitations. It has been used to improve nutrition quality and higher yield in a number of legumes. Dolichos Lablab (Lablab purpureus L) is multipurpose legume that has not been exploited extensively for food nutritional properties through breeding. The purpose of the study was, therefore, to generate awareness that nutritional status of D. Lablab could be improved through mutation induction and be a good source of food components essential for good health. Twenty-four dolichos Lablab germplasms including 20 mutant accessions and 4 commercial genotypes were evaluated for proximate values and mineral contents in Kenya in 2021 based on Association of Official Analytical Chemists (AOAC). Data analysis was based on least significant difference (P = .05).The revealed percent moisture, ash crude fat, crude fibre, crude proteins and total starch content ranged : 7.35% -11.84%, 1.09 -2.90%, 3.35% - 8.05% , 8.86 - 12.70% , 20.03% - 28.87% and 25.50% - 39.00% .The mineral content of phosphorous (P), potassium(K) and calcium (Ca) ranged from 27mg - 57mg, 132mg -297mg and 7mg - 19mg. A significant positive correlation between ash levels to P and K concentration and on P to K concentration. The result of analysis ranked 9 (WT026, WT018 ,MT110 , BT188 , BT032, BT114, MT076 BT137,GT09) different accessions that positively contributed to the nutritional content of the investigated dolichos lablab accessions. Further research on the superior accessions can be done on yield potential, resistance to biotic and abiotic constrains, sensory preferences or used in bio fortification of existing genotypes.

Keragaman Mutan Wijen (Sesamum indicum L.) Berdasarkan Karakter Kualitatif; Diversity of Sesame Mutants (Sesamum indicum L.) Based on Qualitative Characters

<p class="Abstract" align="center"><strong>ABSTRAK</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. adalah salah satu tanaman alternatif penghasil minyak nabati penting. Pendekatan pemuliaan melalui induksi mutasi berusaha untuk menghasilkan variabilitas baru populasi wijen, yang secara umum tersusun dari individu homozigot. Karakter morfologi berguna untuk mengidentifikasi galur dan memastikan hasil pemuliaan mutasi. Tujuan penelitian ini adalah untuk mengevaluasi keragaman morfologi wijen hasil mutasi berdasarkan 26 karakter kualitatif. Penggalian informasi dengan metode analisis kelompok juga dikaji untuk menggambarkan variabilitas genetik pada 57 galur mutan wijen (jenis hitam dan putih) generasi M4 dan M5. Penelitian ini dilakukan dalam dua tahap: tahap pertama terdiri 18 galur generasi M4, dievaluasi pada Maret-Agustus 2015; tahap kedua terdiri atas 39 galur M5, ditanam pada November 2015 hingga April 2016. Pemeriksaan penampilan kualitatif mengikuti panduan <em>descriptor list</em> untuk wijen. Secara umum, penilaian representatif dari sifat kualitatif pada galur mutan wijen generasi M4 akan diikuti oleh keturunan generasi M5. Dendrogram dibangun untuk membedakan galur menjadi kelompok berdasarkan matriks tingkat kemiripan. Struktur populasi utama dari 57 galur berdasarkan sifat kualitatif dikategorikan dalam dua kelompok besar. Materi genotipe kelompok I diklasifikasikan menjadi dua sub-kelompok, terdiri 17 dan 31 galur. Sub-kelompok ini menjadi bagian distribusi genotipe terbesar. Kelompok II tersusun oleh 9 galur, mayoritas dari M4. Nilai korelasi antar karakter bervariasi antara 0,7176 hingga 1,0. Keragaman morfologi antar galur wijen dipengaruhi oleh sifat genetik dibandingkan faktor lingkungan. Studi ini membantu seleksi galur terpilih berdasarkan kestabilan fenotipe. Evaluasi keragaman struktur populasi wijen mutan bermanfaat untuk program pemuliaan.</p><p class="Abstract" align="center"><strong>ABSTRACT</strong></p><p class="Abstract"><em>Sesamum indicum</em> L. is one of the alternative crops that produces vegetative oil. The plant breeding approach through mutation induction could produce new genetic variability in sesame populations, which are generally composed of homozygous individuals. The study aims were to determine the diversity of sesame-mutant lines based on 26 qualitative characters. Cluster analysis method was carried out to describe the genetic variability of 57 sesame mutant lines (consist of black and white types) 4^th (M4) and 5^th generations (M5). The study was done in two phases, the first phases consisted of 18 M4 lines planted in March-August 2015; the second phase consisted 39 M5 lines planted in November 2015 to April 2016. Analyses of qualitative morphological characters followed the descriptors list for sesame. In general, a representative assessment of qualitative traits in M4 lines will be followed by the offspring of M5. Dendrogram showed that the 57 mutant lines categorized into two major clusters. Cluster I were composed of two sub-clusters, consisting 17 and 31 lines. This sub-cluster was the largest part of the genotype distribution. Cluster II composed of 9 lines, where M4 were the majority. The correlation value between characters ranged from 0.7176 up to 1.0. Morphological diversity among lines were largely influenced by genetic rather than environmental factors. This study supports the selection of lines based on phenotype stability. Evaluation of the structural diversity of mutant-sesame populations could be applied in sesame-breeding programs.</p>

CONTRIBUTION OF INDUCED MUTATION IN CROPS TO GLOBAL FOOD SECURITY

Mutation breeding for crop improvement is a technique used for over 70 years. It is a fast way to increase the rate of spontaneous genetic variation in plants contributing to global food security. The genetic variability, created through mutagenesis i.e. physical or chemical, is an important breeding material for developing improved varieties and many studies in the field of functional genomics. The randomly generated heritable genetic changes are expressed in the mutant plants, which are selected for new and useful traits, such as high yielding, disease resistance, tolerance to abiotic stresses and improved nutritional quality. The technique helps to improve the tolerance of crop species to adverse climatic conditions, such as extremes of temperatures, drought, occurrence of pests and diseases. Through support provided by the Joint FAO/IAEA Division, significant agronomic and economic impact has been generated in many countries. The FAO/IAEA Mutant Variety Database (MVD) (http://mvd.iaea.org) demonstrates the significance of mutation induction as an efficient tool in crop improvement. The extensive use of induced mutant germplasms in crop improvement programmes resulted in releasing of more than 3,332 mutant varieties from around 228 crop species (20 July 2020).