Plant Hybridization as an Alternative Technique in Plant Breeding Improvement

Abstract

For ages, plant breeders have relied on the genetic variability that results from sexually crossing plants within the same species. However, the variability that exists within species populations is inadequate, hence the need to exploit desirable traits of interest in distantly related or even unrelated plants through hybridization techniques. Hybridization can be categorized into two; sexual and somatic. Sexual hybridization, also referred to as wide or distant hybridization involves combining two genomes from different parental taxa through pollination, either naturally or by induction. Somatic hybridization involves the fusion of somatic cells instead of gametes, which highly depends on the ability to obtain viable protoplasts and eventually differentiate them to whole plants in vitro. The impacts of hybrids can either be positive or negative. Among the positive attributes of hybrids that have been exploited is heterosis, which results either from dominance, over-dominance or epistasis. Negative ones include sterility, arrested growth of the pollen tube and embryo abortion. To overcome these problems, chromosome doubling, the use of hormones such as 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and embryo rescue have been employed to overcome sterility, arrested growth of pollen tubes and embryo abortion respectively. After the development of hybrids, different hybrid identification techniques have been used to test them such as the use of molecular and morphological markers, cytogenetic analysis and fluorescent in situ hybridization. The use of hybridization techniques in plant improvement remains a vital tool to cross species barriers and utilization of important attributes in unrelated crop plants which could not have been achieved through conventional techniques of plant breeding.

Desarrollo de híbridos de maíz de cruza simple con diferentes estrategias de selección de progenitores

“…Al respecto, en los programas de mejoramiento de maíz (Zea mays L.) han evaluado varios métodos tradicionales y han obtenido diferentes niveles de éxito en la generación de híbridos (Acevedo-Cortés et al, 2020;Ramírez-Díaz et al, 2019;Rodríguez-Pérez et al, 2020); por otro lado, algunos investigadores han considerado el uso de los marcadores moleculares como auxiliar de los métodos tradicionales con la finalidad de predecir el desempeño heterótico de los progenitores al combinar pares de líneas en la formación de híbridos (Beyene et al, 2019, Crossa et al, 2017Lariépe et al, 2017;Marcón et al, 2019;Mwangangi et al, 2019;Nyaga et al, 2020); estas investigaciones han demostrado que el uso de marcadores moleculares son eficientes, ya que pueden dar predicciones precisas con relación a sus parámetros de rendimiento. https://doi.org/10.…”

Evaluación de híbridos F1 de chile (Capsicum annuum) provenientes de cruces entre parentales enfocados en obtener variedades tipo “Blocky o Bell Pepper”

“…El cruzamiento o hibridación constituye el principal medio de mejoramiento genético para obtener nuevos genotipos. A través de la hibridación se logran formas cultivadas superiores a las existentes (Mwangangi et al, 2019). Se define hibridación o cruzamiento como el proceso mediante el cual se cruzan plantas o animales de diferente constitución genética, con el objeto de lograr nuevos genotipos con las características deseables (Goulet et al, 2017).…”

Wheat omics: Classical breeding to new breeding technologies

“…Despite its high potential, the various drawbacks of some hybrid discontinuities are still limited, including infertility, isolation, and sex distortions, high-frequency mutations, chromosome rearrangements, non-disjointment and chromosome rearranging and differences in stems and leaves. The large hybridization techniques need to be further developed as a possible substitute to strategies for genetically modified crop enhancement ( Mwangangi et al, 2019 ).…”