Search

This article explores the applications of fast breeding technologies in crop improvement and functional genomics studies. These technologies, including molecular selection, gene mapping, haploid induction, and genome editing, have greatly expedited the process of modifying crop traits and mapping genes. Examples of these technologies being used include the use of CRISPR/Cas9 to modify crop traits and the development of new haploid inducer lines in various plants. The article also highlights specific research papers on genetic improvement in melon, potato, wheat, rice, and tomato crops using these technologies. Additionally, the document discusses various research papers in the field of plant science, covering topics such as stress tolerance in tomatoes, doubled haploid plants in maize and wheat, and gene exploration in different crops. These papers provide valuable insights into breeding materials, marker development, and the cloning of new genes, contributing to the development of new germplasms and varieties in crops. [Extracted from the article]

There have been a considerable number of studies that have successfully sped up the flowering cycle in woody perennial horticultural species. One particularly successful study in apple (Malus domestica) accelerated flowering using a silver birch (Betula pendula) APETALA1/FRUITFULL MADS-box gene BpMADS4, which yielded a good balance of vegetative growth to support subsequent flower and fruit development. In this study, BpMADS4 was constitutively expressed in European pear (Pyrus communis) to establish whether this could be used as a tool in a rapid pear breeding program. Transformed pear lines flowered within 6-18 months after grafting onto a quince (Cydonia oblonga) rootstock. Unlike the spindly habit of early flowering apples, the early flowering pear lines displayed a normal tree-like habit. Like apple, the flower appearance was normal, and the flowers were fertile, producing fruit and seed upon pollination. Seed from these transformed lines were germinated and 50% of the progeny flowered within 3 months of sowing, demonstrating a use for these in a fast breeding program. [ABSTRACT FROM AUTHOR]

There have been a considerable number of studies that have successfully sped up the flowering cycle in woody perennial horticultural species. One particularly successful study in apple (Malus domestica) accelerated flowering using a silver birch (Betula pendula) APETALA1/FRUITFULL MADS-box gene BpMADS4, which yielded a good balance of vegetative growth to support subsequent flower and fruit development. In this study, BpMADS4 was constitutively expressed in European pear (Pyrus communis) to establish whether this could be used as a tool in a rapid pear breeding program. Transformed pear lines flowered within 6–18 months after grafting onto a quince (Cydonia oblonga) rootstock. Unlike the spindly habit of early flowering apples, the early flowering pear lines displayed a normal tree-like habit. Like apple, the flower appearance was normal, and the flowers were fertile, producing fruit and seed upon pollination. Seed from these transformed lines were germinated and 50% of the progeny flowered within 3 months of sowing, demonstrating a use for these in a fast breeding program.

Rapid cycle breeding uses transgenic early flowering plants as crossbreed parents to facilitate the shortening of breeding programs for perennial crops with long-lasting juvenility. Rapid cycle breeding in apple was established using the transgenic genotype T1190 expressing the BpMADS4 gene of silver birch. In this study, the genomes of T1190 and its non-transgenic wild-type PinS (F1-offspring of ‘Pinova’ and ‘Idared’) were sequenced by Illumina short-read sequencing in two separate experiments resulting in a mean sequencing depth of 182× for T1190 and 167× for PinS. The sequencing revealed 8,450 reads, which contain sequences of ≥20 bp identical to the plant transformation vector. These reads were assembled into 125 contigs, which were examined to see whether they contained transgenic insertions or if they are not using a five-step procedure. The sequence of one contig represents the known T-DNA insertion on chromosome 4 of T1190. The sequences of the remaining contigs were either equally present in T1190 and PinS, their part with sequence identity to the vector was equally present in apple reference genomes, or they seem to result from endophytic contaminations rather than from additional transgenic insertions. Therefore, we conclude that the transgenic apple plant T1190 contains only one transgenic insertion, located on chromosome 4, and shows no further partial insertions of the transformation vector.Accession Numbers: JQ974028.1.

Rapid cycle breeding uses transgenic early flowering plants as crossbreed parents to facilitate the shortening of breeding programs for perennial crops with long-lasting juvenility. Rapid cycle breeding in apple was established using the transgenic genotype T1190 expressing the BpMADS4 gene of silver birch. In this study, the genomes of T1190 and its non-transgenic wild-type PinS (F1-offspring of 'Pinova' and 'Idared') were sequenced by Illumina short-read sequencing in two separate experiments resulting in a mean sequencing depth of 182× for T1190 and 167× for PinS. The sequencing revealed 8,450 reads, which contain sequences of ≥20 bp identical to the plant transformation vector. These reads were assembled into 125 contigs, which were examined to see whether they contained transgenic insertions or if they are not using a five-step procedure. The sequence of one contig represents the known T-DNA insertion on chromosome 4 of T1190. The sequences of the remaining contigs were either equally present in T1190 and PinS, their part with sequence identity to the vector was equally present in apple reference genomes, or they seem to result from endophytic contaminations rather than from additional transgenic insertions. Therefore, we conclude that the transgenic apple plant T1190 contains only one transgenic insertion, located on chromosome 4, and shows no further partial insertions of the transformation vector. Accession Numbers: JQ974028.1. [ABSTRACT FROM AUTHOR]

With an objective to optimize an approach to transfer value-added genes to a wheat variety while maintaining and improving agronomic performance, two alleles ( Als1 and Als2) with mutations in the acetolactate synthase ( ALS) gene located on the long arm of wheat chromosomes 6B and 6D providing tolerance to imazamox herbicide were transferred to Eltan, a popular soft white common winter wheat cultivar in the Pacific Northwest (PNW), USA. Four-step marker-assisted background selection and marker assisted forward breeding approaches were used to develop a wheat variety carrying two genes ( Als1 and Als2) for imazamox tolerance along with improvements in many other agronomic traits. Screening of 1600 BC plants for imazamox tolerance identified 378 plants that were further screened with markers to identify seven plants that were used to make a population of 1400 BC plants, and the selection cycle was repeated. Progeny of 17 selected BCF plants was evaluated for various agronomic and quality parameters to select 12 plants that were increased for field testing. Field evaluation of these lines conducted over 58 location-years along with evaluation in the greenhouse/growth chamber led to the selection of a line 'WA8143' carrying the two genes for imazamox tolerance that yielded >3% higher than Eltan did. With 96.8% similarity to the recurrent parent, WA8143 also showed a better disease resistance package and grain quality needed in a successful Pacific Northwest wheat variety and was subsequently released for cultivation under the name of 'Curiosity CL+.' [ABSTRACT FROM AUTHOR]