Spinach is a highly nutritive and medicinally important leafy vegetable cultivated in many countries worldwide. Diversity in the gene pool of a species may affect the adaptability to a new environment as well as to develop new varieties more tolerant to stress and pathogens. To assess the genetic variability of species, morphological traits are considered as the simplest markers. Therefore, a field experiment was conducted to explore the genetic diversity of spinach germplasm from 30 different countries, using agro-morphological traits. Data was based on 21 morphological characters, analyzed by multivariate statistical tools. Plant height, petiole attitude, leaf size, and leaf shape were the characters showing significant variations. Based on geographical distribution, the germplasm of Turkey and China was found to be more diverse, followed by Afghanistan and Pakistan. Results concluded that the studied germplasm possessed an important source of highly diverse agronomic traits that should be conserved for future spinach breeding programs.

Non-coding RNAs (ncRNAs) are functional low proteinic RNAs. Initially the discovery of ncRNA was delayed due to the thought that they do not contain any protein content and therefore are useless. However, in the last ten years, the advancement of RNA sequencing technology has played a vital role in its discovery and potential. Based on the size and shape differentiation, ncRNAs are divided into small ncRNA (sRNA), medium-sized ncRNA and long ncRNA (lncRNA) as well as linear or circular. According to recent reports lncRNAs are functional in regulating several kinds of biotic and abiotic stresses in plants. Therefore, in this chapter role of ncRNA in regulating abiotic stress through gene expression has been described. However, there is more research required to discover the role of ncRNAs in the cellular pathways.