Editor’s Choice Articles

Amid a rapidly growing global population and increasing threats to crop yields, this review focuses on Speed Breeding (SB) in crop genetics. It traces SB’s development from carbon arc lamp experiments 150 years ago to its modern use with LED technology which significantly accelerates breeding cycles. SB has applications in genetic mapping, genetic modification, and trait stacking, enhancing crop resilience by leveraging allelic diversity. It aligns well with breeding methods like single plant selection and single seed descent. The integration of SB with gene editing, genotyping, and genomic selection holds great promise. However, SB faces challenges related to infrastructure, genotypic variations, and potential stress responses. In summary, SB is a powerful and promising approach to address food security concerns and advancing crop genetics. Full article

Trichoderma fungi are promising candidates for biocontrol agents and plant growth promoters. Trichoderma atrobrunneum and T. simmonsii were evaluated for the control of soil-borne phytopathogenic fungi, in the present study. Dual culture tests with Rhizoctonia solani and Fusarium oxysporum f. sp. lycopersici were used to conduct in vitro evaluation. In the presence of Trichoderma, phytopathogen’s growth rate was inhibited up to 59.70% for R. solani and 42.57% for F. oxysporum. Greenhouse trials with potted tomato plants demonstrated that Trichoderma caused a significant increase of stem height and fresh stem weight in pathogen-inoculated plants, compared with the negative control (plants artificially inoculated with the phytopathogen only). Except for T. simmonsii, plant growth was not significantly enhanced by a Trichoderma presence in the positive control (healthy plants). The overall performance of the two Trichoderma species studied was equivalent to that of the T. harzianum T22 commercial strain. All the tested species were found to be effective in suppressing colony growth and disease development of the soil borne pathogens in dual cultures and potted plants, indicating that they could be used as biocontrol agents. Our findings are discussed in the context of enhancing endophytic microorganisms’ application in crop production systems. Full article

Protected cropping offers a way to bolster food production in the face of climate change and deliver healthy food sustainably with fewer resources. However, to make this way of farming economically viable, we need to consider the status of protected cropping in the context of available technologies and corresponding target horticultural crops. This review outlines existing opportunities and challenges that must be addressed by ongoing research and innovation in this exciting but complex field in Australia. Indoor farm facilities are broadly categorised into the following three levels of technological advancement: low-, medium- and high-tech with corresponding challenges that require innovative solutions. Furthermore, limitations on indoor plant growth and protected cropping systems (e.g., high energy costs) have restricted the use of indoor agriculture to relatively few, high value crops. Hence, we need to develop new crop cultivars suitable for indoor agriculture that may differ from those required for open field production. In addition, protected cropping requires high start-up costs, expensive skilled labour, high energy consumption, and significant pest and disease management and quality control. Overall, protected cropping offers promising solutions for food security, while reducing the carbon footprint of food production. However, for indoor cropping production to have a substantial positive impact on global food security and nutritional security, the economical production of diverse crops will be essential. Full article

Sporisorium reilianum causes head smut in sorghum. A total of 36 Senegalese sorghum accessions comprised of sorghum lines that have not been explored with response to pathotype 5 of S. reilianum were evaluated with 3 different treatments. First, seedling shoots were inoculated while still in soil with teliospores in agar, and then submerged under water at 4 days post inoculation. Signs of infection (noticeable spots) on the first leaf were observed up to 6 days post submergence. Second, seedlings at the same stage were inoculated by placing the teliospore impregnated agar around the stem in pots, moved to a greenhouse and grown to full panicle development stage. Third, seedings were inoculated via syringe inoculation in the greenhouse. Although soil inoculated seedlings grown in the greenhouse did not result in systemic infection as determined by lack of symptoms at panicle exsertion, 88.9% of tested cultivars showed systemic infections when syringe inoculated in the greenhouse. Inoculation of seedlings maintained under water led to broad range of noticeable spots that are assumed to be potential infection sites based on a previous study. In addition, seedling inoculation led to slightly upregulated expression of chitinase and PR10, genes that are associated with defense in aerial parts of plants. Full article

The present study investigated the distribution status and biodiversity of Trichoderma species surveyed from coffee rhizosphere soil samples from Ethiopia and their potential for biocontrol of coffee wilt disease (CWD) caused by Fusarium xylarioides. Trichoderma isolates were identified based on molecular approaches and morphological characteristics followed by biodiversity analysis using different biodiversity indices. The antagonistic potential of Trichoderma isolates was evaluated against F. xylarioides using the dual confrontation technique and agar diffusion bioassays. A relatively high diversity of species was observed, including 16 taxa and 11 undescribed isolates. Trichoderma asperellum, T. asperelloides and T. longibrachiatum were classified as abundant species, with dominance (Y) values of 0.062, 0.056 and 0.034, respectively. Trichoderma asperellum was the most abundant species (comprising 39.6% of all isolates) in all investigated coffee ecosystems. Shannon’s biodiversity index (H), the evenness (E), Simpson’s biodiversity index (D) and the abundance index (J) were calculated for each coffee ecosystem, revealing that species diversity and evenness were highest in the Jimma zone (H = 1.97, E = 0.76, D = 0.91, J = 2.73). The average diversity values for Trichoderma species originating from the coffee ecosystem were H = 1.77, D = 0.7, E = 0.75 and J = 2.4. In vitro confrontation experiments revealed that T. asperellum AU131 and T. longibrachiatum AU158 reduced the mycelial growth of F. xylarioides by over 80%. The potential use of these Trichoderma species for disease management of F. xylarioides and to reduce its impact on coffee cultivation is discussed in relation to Ethiopia’s ongoing coffee wilt disease crisis. Full article

Legume seeds are often sown on standing rice crops a few weeks before rice harvest (relay cropping). Seeds cannot germinate in waterlogged soil under relay sowing as oxygen is depleted. However, seeds may survive under soil waterlogging if the seeds can initiate anaerobic respiration, have a large seed reserve such as carbohydrates, perform a slow water uptake during imbibition and are small in size. An example of a seed crop that can initiate anaerobic respiration is rice. The seed embryo of rice can use an alcoholic fermentation pathway from carbohydrates to produce enough energy to germinate. In legumes, seeds with a slow imbibition rate were more waterlogging tolerant than seeds with a rapid rate. This is likely due to seeds with low imbibition rates having less electrolyte leakage than seeds with a rapid imbibition rate during germination under waterlogging. A small amount of oxygen may remain on the surface of waterlogged soil. Small seeds can use the small amount of oxygen on the surface of waterlogged soil to germinate. However, large seeds often fail to use the oxygen on the surface of waterlogged soil to germinate because only a small part of large seeds remain on the surface of waterlogged soil. Therefore, small seeds are more adapted to soil waterlogging than large seeds under relay cropping. This review is focused on the physiological adaptation of legume seeds under low oxygen concentration during soil waterlogging. Full article

Stripe rust is a devastating disease in wheat that causes substantial yield loss around the world. The most effective strategy for mitigating yield loss is to develop resistant cultivars. The wild relatives of wheat are good sources of resistance to fungal pathogens. Here, we used a genome-wide association study (GWAS) to identify loci associated with stripe rust (causal agent: Puccinia striiformis f. sp. tritici) resistance in wild emmer (Triticum dicoccoides) at the seedling stage, in the greenhouse, and at the adult plant stage, in the field. We found that the two major loci contributing to resistance in our wild emmer panel were the previously cloned seedling-stage resistance gene, Yr15, and the adult-plant-stage resistance gene, Yr36. Nevertheless, we detected 12 additional minor QTLs that additionally contribute to adult plant resistance and mapped a locus on chromosome 3AS that tentatively harbors a novel seedling resistance gene. The genotype and phenotype data generated for the wild emmer panel, together with the detected SNPs associated with resistance to stripe rust, provide a valuable resource for disease-resistance breeding in durum and bread wheat. Full article

Tomato continues to be one of the most important crops worldwide, and protected cultivation is practiced to overcome the biotic and abiotic stresses to which the plant are exposed during growth. In this study we evaluated the effect of colored net houses on the growth, yield and nutritional values, as well as the incidence of common pests under three different light conditions: (1) colored (magenta), (2) conventional (white), and open field conditions. A colored net house led the plants to grow taller with higher lycopene content, but recorded a higher number of whiteflies, compared to the conventional net house and open field conditions. Furthermore, plants under protected structures recorded lower SPAD values, but larger terminal leaflets, lower damage by leaf miners, but more damage caused by spider mites compared to those plants grown under open field conditions. Overall, we found that the use of colored net houses provided a positive effect on tomato production in terms of improvement in morphometric parameters, however, to obtain higher yields under this production system, it is important to reduce the elevated temperature and increase the relative humidity inside the protective structures to be adapted for local growing conditions in Taiwan. Full article

Collection of wheat landraces (WLR) was conducted in Afghanistan, Iran, and Turkey in 2010–2014. A representative subset of this collection was used in the current study and included 45 bread wheat landraces from Turkey, 19 from Iran, and 20 from Afghanistan. This material was supplemented by 73 modern cultivars and breeding lines adapted to semiarid conditions and irrigated conditions. Overall, 157 genotypes were tested in Turkey in 2018 and 2019 and in Afghanistan and Iran in 2019 under rainfed conditions to compare performance of WLR and modern material. The germplasm was genotyped using a high density Illumina Infinium 25K wheat SNP array and KASP markers for agronomic traits. The average grain yield ranged between 2.2 and 4.0 t/ha depending on the site and year. Three groups of landraces demonstrated similar average grain yield, though Afghanistan material was slightly higher yielding not only in Afghanistan but also in Turkey. Modern material outyielded the landraces in two environments out of four. The highest yielding landraces were competitive with the best modern germplasm. Frequency of gene Sus2-2B affecting 1000 kernel weight was 64% in WLR and only 3% in modern material. Presence of positive allele of Sus2-2B increased 1000 kernel weight by nearly 4%. Breeding strategy to improved landraces and modern cultivars is discussed. Full article

The composition of apples varies with both cultivar and horticultural practice. Knowledge about the chemical composition of different cultivars in particular sugars, organic acids, nitrogen compounds and polyphenols is essential, since they are directly related to the progress of fermentation monitoring and the organoleptic qualities of produced ciders. Fifteen apple cultivars grown in two locations in Norway were investigated for their chemical composition, including polyphenol profiles. The nitrogen content varied from 43.2 to 171.4 mg N/L between the cultivars, and the sum of free amino acids varied from 42.4 to 924.5 mg/kg. Asparagine, aspartic acid and glutamic acid were the dominating amino acids. Flavanols, consisting of catechins and procyanidins, were the dominating polyphenols, followed by hydroxycinnamic acids. The cultivar Bramley Seedling was highest in the sum of polyphenols by HPLC (1838 mg/L) and relatively low in nitrogen content (75 mg N/L). Summerred was lowest in the sum of polyphenols (87 mg/L) and highest in nitrogen (171.4 mg N/L). Sugar content, measured as density in the juice, varied between 1034 and 1060 g/L. Using cider categorization of apples, ’Bramley Seedling’ would be defined as sharp, while the others are sweet cultivars. Full article