Reduced viscosity mutants of Trichoderma reesei with improved industrial fermentation characteristics

Morphological mutants of Trichoderma reesei were isolated following chemical or insertional mutagenesis. The mutant strains were shown to have reduced viscosity under industrially-relevant fermentation conditions and to have maintained high specific productivity of secreted protein. This allowed higher biomass concentration to be maintained during the production phase and, consequently, increased volumetric productivity of secreted protein. The causative mutations were traced to four individual genes (designated sfb3, ssb7, seb1 and mpg1). We showed that two of the morphological mutations could be combined in a single strain to further reduce viscosity and enable a 100 per cent increase in volumetric productivity.

Effect of Ethyl Methanesulfonate on Induced Morphological Variation in M3 Generation of Chrysanthemum indicum var. aromaticum

Mutation breeding is considered to be economic and efficient in plant improvement, and the use of chemical mutagens such as ethyl methanesulfonate (EMS) can potentially address plant breeding challenges. The aim of this study was to induce morphological mutants in C. indicum var. aromaticum using EMS treatments with different doses, and to analyze the morphological and physiological traits of obtained mutants in expectation of finding favorable mutants. Results revealed significant effects of EMS doses on seed germination. The sample germination rate significantly decreased with increasing of EMS doses. The obtained morphological mutants were two viable types, containing leaf and stem mutants. Overall leaf size was significantly larger as a result of EMS treatments. And the height of mutant plants was significantly higher. Anatomical characteristics exhibited changes in both leaves and stems of the mutant plants. The puncture strength of the bent stem from the mutant plants was low, with weak penetration resistance. The total lignin and cellulose contents of mutant plants stem decreased significantly as a result of the EMS treatments. These results demonstrate the efficiency of EMS to induce mutations in C. indicum var. aromaticum, and this method can be useful in the future to assist breeding of this plant.

Antifungal activity of Rauwolfia serpentina root extract against Neurospora crassa and genetic study of induced mutants

Rauwolfia serpentina (R. serpentina) root extract was used to study antifungal activity against Neurospora crassa (Ema) as well as mutation, mating type, segregation of the fungus. It was found that more concentration of root extract was used in VM media, higher antifungal activity was observed. After mutation in N. crassa conidia with root extract of R. serpentina, 5 groups of morphological mutants viz. albino (al 98), vigorous (vg 77), fluffy (fl 139), conidial band (con.band 221) and cauliflower (clf 155) were obtained. From genetic study, it was found that all the mutants formed perithecia crossing with EmA which confirmed that mating type of all the mutants is ‘a’ and is not changed due to mutation. Besides, segregation ratio between mutant and wild isolates was about 1:1 which confirmed that mutation takes place in the nuclear gene, not cytoplasmic. Bangladesh J. Sci. Ind. Res.54(3), 241-246, 2019

Induced Mutagenesis for the Creation of New Starting Material in Sunflower Breeding

The article colligates data of studies on the variability of quantitative and qualitative traits in mutant sunflower M1-M3 generations affected by dimethyl sulfate (DMS) (0.01, 0.05 %) and gamma rays (120; 150 Gy), frequencies and range of mutations in M2 and their inheritance in mutant families, chromosome aberrations in meiosis, as well as on the breeding and genetic value of induced mutants and possibilities of their use in breeding. The methodical peculiarities of the mutational breeding of the cross-pollinating crop were defined, and new mutants with changed features were created.Investigating new homozygous self-pollinated sunflower lines, we observed a more negative mutagenic impact of gamma irradiation (120 and 150 Gy) on the germinability of M1 sunflower seeds in the field compared with the DMS effect (0.01 and 0.05 %). The field germinability of DMS-treated seeds was 83–87 % vs. 11–15 % of gamma-irradiated ones.The mutagenic effect of gamma rays (120 and 150 Gy) on M1 meiosis was shown to be stronger than that of DMS (0.01 and 0.05 %). The percentage of cells with alterations varied within 15.79–18.78 % (120 Gy) and 20.38–25.26 % (150 Gy) compared to 0–0.16 % in the control.The effect of gamma rays on the frequency of morphoses in M1 was stronger, in particular, after exposure to 120 Gy or 150 Gy of gamma irradiation, the number of plants with alterations was 43 %, whereas after DMS treatment (0.01 and 0.05 %) this parameter averaged 27–28 %.We determined the inheritance of mutations of quantitative and qualitative traits, which are important for breeding, in mutant M2 families and selected mutant families with inherited altered traits that can be considered as mutations. Among the best mutations, there are morphological mutants with marker traits, mutants with increased content of oil in seeds, increased 1000-seed weight, increased contents of behenic, linoleic and palmitoleic acids as well as with absolute resistance to downy mildew.

Morphological mutants of Zoysia japonica Steud. induced by gamma ray irradiation

Study of Zoysia japonica morphological improvement and breeding by induced mutation using gamma ray irradiation was conducted. Mutagenesis by gamma ray irradiation was employed using 0, 20, 40, 60, 80, 100, 120 and 140 Gy to treat 30 single node stolons per treatment. It was demonstrated that single node stolon is suitable for gamma ray irradiation mutagenesis in Z. japonica. It has been identified that 76 Gy as the value LD50 is effective to induce mutagenesis on Z. japonica. Survival rate of Z. japonica stolon was greatly reduced when irradiated with higher dosages. This experiment was repeated using LD50 on 1500 single node stolons. Thirty nine morphological mutants were identified and evaluated. Most of the mutants were semi-dwarf and have horizontal growing pattern with reduced internode length and leaf blade length. The altered morphological traits were stable after third cutting back (M1V3) shown by their morphological performance. Mutation breeding is effective in improving Z. japonica when easily recognized cultivars are needed.

Induce Physical and Chemical Mutagenesis for Improvement of Yield Attributing Traits and their Correlation Analysis in Chickpea

In the current scenario of sky high population and widespread food insecurity, there is an urgent need for productivity improvement of major crops like pulses, one of the most climate friendly and accessible foods for the large poor population of the world. Chickpea is an important pulse crop, having high percentage of nutritional content and is widely used as food across the world. Induced mutagenesis has proved over time as a coherent tool for modern plant breeders to improve the productivity for combating the food insecurity and malnutrition across the globe. Dry and healthy seeds of Cicer arietinum L. var. C-235 were treated with individual and combination doses of gamma rays, sodium azide and hydrazine hydrate to raise the M1 generation. M2 seeds harvested from M1 plants were sown in the nest season.Bio-physiological study in M1 generation showed growth inhibition in the order viz. combination treatment>hydrazine hydrate>gamma rays>sodium azide. In M2 generation, comparative observations were recorded for morphological variation and quantitative traits to assess the genetic response of the chickpea variety C-235 toward the different concentrations of mutagens. Observations on isolated mutants in M2 generation revealed that 0.3% HZ + 0.02% SA was most mutagenic while 200 Gy, 0.03% SA and 0.2% HZ were highest in their individual treatment groups. In context to the frequency of morphological mutants studied in M2 generation, dwarf mutants were found to be highest followed by tall and branching pattern mutants. Highly significant correlation coefficient between yield and other traits showed that the selection for high yielding mutants can be done on the basis of these traits undoubtedly.

Mutational Changes In Delphinium malabaricum (Huth.) Munz.: A Potential Ornamental Plant

Mutation breeding is an established method used for crop improvement and has played a major role in the development of many new flower color/shape mutant cultivars in ornamentals. The present study is aimed at inducing mutations inDelphinium malabaricumusing chemical mutagens ethyl methane sulfonate (EMS), sodium azide (SA) and physical mutagen (gamma rays). It was observed thatD. malabaricummanifested specific reactions to the treatments with EMS, SA and gamma rays. Identification and selection of mutations were carried out in the second generation (M2). A variety of chlorophyll deficient mutants and high percentage of the flower color and morphological mutants were recorded. The maximum frequency of chlorophyll and flower color and morphological mutations were recorded in EMS treated plants when compared to the other two mutagens. The frequency values for the individual mutant types were varied and randomly distributed at different mutagenic treatments. The highest percentage of color mutants arose after treatments with 0.25% of EMS and the lowest at 20 kR of gamma rays. The mutants were quite distinct, as compared to the control and often had more attractive ornamental features compared to the starting material. The major commercial benefit of the application of this technology has so far been obtaining of novel flower mutants that can be used as an initial material for further breeding of new cultivars.