Sporogenesis in F1 hybrids from the crosses between common wheat and lines with introgressions from Amblyopyrum muticum

Hybridization of wheat lines comprising fragments of alien genetic material (introgression) with common wheat cultivars is effective and widespread means of transferring alien genes into genomes of modern wheat cultivars, and remains the main method of expending genetic pool of common wheat using genes of wild relatives. Success of such transfer depends on the processes of sporo- and gametogenesis in F1 hybrids, therefore cytological assessment of this processes is obligatory. Stages of meiosis and microgametogenesis were studied on cytological preparations of spikes of F1 hybrids from reciprocal crosses of common wheat cultivars and wheat lines of introgression origin with alien genetic material from wheat wild relative Amblyopyrum muticum. Sporogenesis in F1 hybrids occurs with disorders in both male and female sexual areas. Instead of 21 closed bivalents chromosome configurations in maximal association of chromosomes in M1 PMC could contain up to 8 open bivalents, up to 12 univalents, including three- and quadrivalents. In A1 lagging chromatids were observed, and up to 5 micronuclei per cell were registered in tetrads. Quantitative characteristics of chromosome associations in M1 PMC did not differ for hybrids obtained using introgression lines as female (direct crossing) and male (reverse crossing) cross components. The difference between reciprocal crosses was detected only for the quantity of cells in tetrads with different quantity of micronuclei. F1 hybrids from direct crosses had smaller portion of cells without micronuclei, and more cells with 1-3 micronuclei compared to hybrids of reverse crosses.

Lifelong Consumption of Plant-Based GM Foods

Genetically modified (GM) crops are cultivated in over 30 countries with their products and by-products imported by over 60 countries. This chapter seeks to highlight general concerns and potential lifelong effects of consuming GM plant-based food. The consumption of GM plant-based food is as risky as consuming conventional plant-based food. However, the alien genes in these products may be unstable leading to antinutritional and unintended short-term consequences. Due to the paucity of research, no long-term effects have been attributed to the lifelong consumption of these products. Nonetheless, possible lifelong health and socioeconomic effects may result from outcrossing of genes, increasing antibiotic resistance, development of new diseases, as well as potential effects on the environment and biodiversity. Biotechnology companies need to invest more in interdisciplinary research addressing the potential lifelong effects of these products. Although GM foods are safe for consumption, clarification of current risks and lifelong effects are required.

Engineered Durum Wheat Germplasm with Multiple Alien Introgressions: Agronomic and Quality Performance

If genetic gains in wheat yield are to be achieved in today’s breeding, increasing the genetic variability of cultivated genotypes is an essential requisite to meet. To this aim, alien gene transfer through chromosome engineering (CE) is a validated and sound strategy. Attempts to incorporate more than one alien segment into cultivated wheat have been rare, particularly for tetraploid durum wheat. Here, we present the agronomic and quality performance of the first successful CE-mediated multiple introgression into the latter species. By assembling into 7AL, 3BS, and 1AS arms of a single genotype homoeologous segments of Thinopyrum ponticum 7el1L, Aegilops longissima 3SlS, and Triticum aestivum 1DS arms, respectively, we have stacked several valuable alien genes, comprising Lr19+Sr25+Yp (leaf and stem rust resistance and a gene increasing semolina yellowness), Pm13 (powdery mildew resistance), and Gli-D1/Glu-D3 (genes affecting gluten properties), respectively. Advanced progenies of single, double, and triple recombinants were field-tested across three years in a typical durum wheat growing area of central Italy. The results showed that not only all recombinants had normal phenotype and fertility, but also that one of the triple recombinants had the highest yield through all seasons compared with all other recombinants and control cultivars. Moreover, the multiple introgressions enhanced quality traits, including gluten characteristics and semolina yellow index. The presence of effective disease resistance genes confers additional breeding value to the novel and functional CE products, which can greatly contribute to crop security and safety.

Engineered Durum Wheat Germplasm with Multiple Alien Introgressions: Agronomic and Quality Performance

If genetic gains in wheat yield are to be achieved in today’s breeding, increasing genetic variability of cultivated genotypes is an essential requisite to meet. To this aim, alien gene transfer through chromosome engineering (CE) is a validated and sound strategy. Attempts to incorporate more than one alien segment into cultivated wheat have been rare, particularly for tetraploid durum wheat. Here we present the agronomic and quality performance of the first successful CE-mediated multiple introgression into the latter species. By assembling into 7AL, 3BS and 1AS arms of a single genotype homoeologous segments of Thinopyrum ponticum 7el1L, Aegilops longissima 3SlS, and Triticum aestivum 1DS arms, respectively, we have stacked several valuable alien genes, comprising Lr19+Sr25+Yp (leaf and stem rust resistance and a gene increasing semolina yellowness), Pm13 (powdery mildew resistance) and Gli-D1/Glu-D3 (genes affecting gluten properties), respectively. Advanced progenies of single, double and triple recombinants were field-tested across three years in a typical durum wheat growing area of Central Italy. The results showed that not only all recombinants had normal phenotype and fertility, but also that one of the triple recombinants had the highest yield through all seasons compared with all other recombinants and control cultivars. Moreover, the multiple introgressions enhanced quality traits, including gluten characteristics and semolina yellow index. Presence of effective disease resistance genes confers additional breeding value to the novel and functional CE products, which can greatly contribute to crop security and safety.

Lifelong Consumption of Plant-Based GM Foods

Genetically modified (GM) crops are cultivated in over 30 countries with their products and by-products imported by over 60 countries. This chapter seeks to highlight general concerns and potential lifelong effects of consuming GM plant-based food. The consumption of GM plant-based food is as risky as consuming conventional plant-based food. However, the alien genes in these products may be unstable leading to antinutritional and unintended short-term consequences. Due to the paucity of research, no long-term effects have been attributed to the lifelong consumption of these products. Nonetheless, possible lifelong health and socioeconomic effects may result from outcrossing of genes, increasing antibiotic resistance, development of new diseases, as well as potential effects on the environment and biodiversity. Biotechnology companies need to invest more in interdisciplinary research addressing the potential lifelong effects of these products. Although GM foods are safe for consumption, clarification of current risks and lifelong effects are required.

Chromosome aberrations induced by zebularine in triticale

Chromosome engineering is an important approach for generating wheat germplasm. Efficient development of chromosome aberrations will facilitate the introgression and application of alien genes in wheat. In this study, zebularine, a DNA methylation transferase inhibitor, was successfully used to induce chromosome aberrations in the octoploid triticale cultivar Jinghui#1. Dry seeds were soaked in zebularine solutions (250, 500, and 750 μmol/L) for 24 h, and the 500 μmol/L treatment was tested in three additional treatment times, i.e., 12, 36, and 48 h. All treatments induced aberrations involving wheat and rye chromosomes. Of the 920 cells observed in 67 M1 plants, 340 (37.0%) carried 817 aberrations with an average of 0.89 aberrations per cell (range: 0–12). The aberrations included probable deletions, telosomes and acentric fragments (49.0%), large segmental translocations (28.9%), small segmental translocations (17.1%), intercalary translocations (2.6%), long chromosomes that could carry more than one centromere (2.0%), and ring chromosomes (0.5%). Of 510 M2 plants analyzed, 110 (21.6%) were found to carry stable aberrations. Such aberrations included 79 with varied rye chromosome numbers, 7 with wheat and rye chromosome translocations, 15 with possible rye telosomes/deletions, and 9 with complex aberrations involving variation in rye chromosome number and wheat–rye translocations. These indicated that aberrations induced by zebularine can be steadily transmitted, suggesting that zebularine is a new efficient agent for chromosome manipulation.