**Genomics and Biotechnologies in Horticulture**

Horticultural plants encompass a diverse range of botanical species characterized by unique biological traits. They often necessitate controlled environments for optimal growth, rely on grafting techniques for propagation, and possess the ability for asexual reproduction. These plants hold immense economic and cultural significance for humankind. Currently, more than 200 horticultural plant species, including fruit trees, vegetables, flowers, medicinal plants, and beverage crops, have been subjected to genomic sequencing [1]. Remarkable strides have also been achieved in the fields of genome genotyping, pan-genomics, and the assembly of telomere-to-telomere genomes [2], marking an unprecedented advancement in our understanding of these plants.

Currently, the rapid development and application of multi-omics technologies, such as phenomics, metabolomics, and hormone profiling, as well as various gene editing technologies such as CRISPR-Cas, have greatly facilitated plant gene function research and the molecular breeding of new cultivars.

#### **The Molecular Mechanisms of Horticultural Plant Adaptation to the Environment**

Environmental adaptation is a key characteristic of horticultural plants for their growth and reproduction under various environmental conditions. However, the study of horticultural plants lags behind model plants due to their diverse traits. With the decoding of the genomes of many horticultural plants and breakthroughs in various biotechnological approaches, significant progress has been made in the molecular genetics of horticultural plants. Identifying important genes is crucial in the face of various stresses. In this Special Issue, *PebHLH56* in passion fruit was found to be involved in cold stress [3]; SOD in water lilies is associated with temperature stress and heavy metal stress [4]; and lncRNA participates in plant–pathogen interactions in tomatoes [5]. Furthermore, in addressing various disease and pest problems, Chae et al. identified key genomic loci and alleles that play critical roles in pepper disease resistance through quantitative trait locus (QTL) analysis. These research findings will provide references for the development of SNP markers associated with pepper disease resistance QTLs and the breeding of disease-resistant pepper cultivars [6]. Shao et al., exploring the duplication/loss of NLR genes in Asteraceae species, discovered a unique evolutionary pattern of "expansion followed by contraction" in NLR

**Citation:** Liang, Y.; Chen, F.; Xue, J.-Y. Genomics and Biotechnology Empower Plant Science Research. *Horticulturae* **2023**, *9*, 863. https:// doi.org/10.3390/horticulturae9080863

Received: 9 July 2023 Accepted: 17 July 2023 Published: 28 July 2023

**Copyright:** © 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/).

genes, thus establishing the NLR gene repertoire in Asteraceae plants and revealing the genetic basis of disease resistance in Asteraceae plants [7].
