Toward a Sustainable Agriculture Through Plant Biostimulants

Over the past decade, interest in plant biostimulants has been on the rise, compelled by the growing interest of researchers, extension specialists, private industries, and farmers in integrating these products in the array of environmentally friendly tools to secure improved crop performance, nutrient efficiency, product quality, and yield stability. Plant biostimulants include diverse organic and inorganic substances, natural compounds, and/or beneficial microorganisms such as humic acids, protein hydrolysates, seaweed and plant extracts, silicon, endophytic fungi like mycorrhizal fungi, and plant growth-promoting rhizobacteria belonging to the genera Azospirillum, Azotobacter, and Rhizobium. Other substances (e.g., chitosan and other biopolymers and inorganic compounds) can have biostimulant properties, but their classification within the group of biostimulants is still under consideration. Plant biostimulants are usually applied to high-value crops, mainly greenhouse crops, fruit trees and vines, open-field crops, flowers, and ornamentals to sustainably increase yield and product quality. The global biostimulant market is currently estimated at about $2.0 billion and is expected to reach$3.0 billion by 2021 at an annual growth rate of 13%. A growing interest in plant biostimulants from industries and scientists was demonstrated by the high number of published peer-reviewed articles, conferences, workshops, and symposia in the past ten years. This book compiles several original research articles, technology reports, methods, opinions, perspectives, and invited reviews and mini reviews dissecting the biostimulatory action of these natural compounds and substances and beneficial microorganisms on crops grown under optimal and suboptimal growing conditions (e.g., salinity, drought, nutrient deficiency and toxicity, heavy metal contaminations, waterlogging, and adverse soil pH conditions). Also included are contributions dealing with the effect as well as the molecular and physiological mechanisms of plant biostimulants on nutrient efficiency, product quality, and modulation of the microbial population both quantitatively and qualitatively. In addition, identification and understanding of the optimal method, time, rate of application and phenological stage for improving plant performance and resilience to stress as well as the best combinations of plant species/cultivar × environment × management practices are also reported. We strongly believe that high standard reflected in this compilation on the principles and practices of plant biostimulants will foster knowledge transfer among scientific communities, industries, and agronomists, and will enable a better understanding of the mode of action and application procedures of biostimulants in different cropping systems

Diversity, Interaction and Bioprospecting of Plant-Associated Microbiomes

Numerous studies have demonstrated that the plant microbiome is highly relevant for the growth and fitness of plants. Plants in ecosystems and agroecosystems can recruit a wide variety of microorganisms, including beneficial microbes which are being studied and applied as biostimulators to improve nutrition and tolerance of plants and as biocontrol of phytopathogens. In this context, this Book contains a selection of articles describing diverse ecological and biotechnological aspects of microbiomes in native and agronomic plants (e.g., pepper, potato, rice and lettuce) created by researchers from Italy, China, Korea, Egypt, Oman, Germany, the USA, and Chile

SSR analysis of molecular variance (AMOVA) for red clover genotypes

Red clover (Trifolium pratense L.) is forage legume with multipurpose value and evaluation of its genetic diversity is fundamental for its breeding. Plant material in this investigation consisted of 46 red clover accessions that came from throughout the world and our experiment was evaluated based on a trial that was set up in a randomized block design with three replications according to the UPOV descriptor (2001). The traits of interest were following agronomical and quality properties: number of internodes (NOI), stem length (STL), yield of green mass (YGM), yield of dry matter (YDM), crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF). In the evaluation of red clover genotypes that were grouped according to the agronomical and chemical traits, the genotypes were separated into four clusters. The determined sample segregation was tried to interconnect with DNA level variation. Analysis of molecular variance (AMOVA) based on 14 Simple sequence repeats (SSR) was performed to assess genetic variation within and between red clover populations that were previously clustered. AMOVA did not show statistically significant intergroup differentiation. The index of genetic differentiation (ΦST) among groups was also estimated using the AMOVA procedure and it revealed weak genetic differentiation between these four clusters. As in many other marker supported experiments, in this investigation, AMOVA showed that the larger proportion of variation resided within population level

Variability of tillering in winter wheat (Triticum aestivum L.)

Variability of length of spike and number of spikelets spike-1 have share in forming of grain yield of wheat. The aim of this study was estimation of variability of length of spike and number of spikelets spike-1 in 20 genetically divergent wheat cultivars grown in different environmental conditions. The experiment was set up as a randomised block design in three replications. Obtained results indicated differences in average values of length of spike and number of spikelets spike-1 among tested cultivars in both years of experiment. In average for all cultivars length of spike was higher in the second year than in first year of experiment. Also, average value of number of spikelets spike-1 was higher in second year at the analysed wheat cultivars. The wheat cultivar Dejana expressed the highest length of spike (12.50cm) in average in the second experimental year while the wheat cultivar Sumadinka had the least length of spike (8.91cm) in average in the first year. Based on the results was established, variability of wheat cultivars for the both analysed traits of spike, as well as, significant differences between the wheat cultivars according to length of spike and number of spikelets spike-1 , which are in dependence of genetic and environmental factors