Low Disease Susceptibility Research Articles

Review on camel genetic diversity: ecological and economic perspectives.

Camels, known as the "Ship of the Desert," play a vital role in the ecosystems and economies of arid and semi-arid regions. They provide meat, milk, transportation, and other essential services, and their resilience to harsh environments makes them invaluable. Despite their similarities, camel breeds exhibit notable differences in size, color, and structure, with over 40million camels worldwide. This number is projected to increase, underscoring their growing significance. Economically, camels are crucial for food production, tourism, and trade, with camel racing being particularly significant in Arab countries. Their unique physiological traits, such as low disease susceptibility and efficient water conservation, further enhance their value. Camel products, especially meat and milk, offer substantial nutritional and therapeutic benefits, contributing to their high demand. Genetic diversity studies have advanced our understanding of camels' adaptation to extreme environments. Functional genomics and whole-genome sequencing have identified genes responsible for these adaptations, aiding breeding programs and conservation efforts. High-throughput sequencing has revealed genetic markers linked to traits like milk production and disease resistance. The development of SNP chips has revolutionized genetic studies by providing a cost-effective alternative to whole-genome sequencing. These tools facilitate large-scale genotyping, essential for conserving genetic diversity and improving breeding strategies. To prevent the depletion of camel genetic diversity, it is crucial to streamline in situ and ex situ conservation efforts to maintain their ecological and economic value. A comprehensive approach to camel conservation and genetic preservation, involving advanced genomic technologies, reproductive biotechniques, and sustainable management practices, will ensure their continued contribution to human societies.

Cultivating Resilience: Disease Resistance Screening of Buckwheat (Fagopyrum spp.) Genotypes in India's Semi-tropical Belt

Buckwheat (Fagopyrum spp.) is a major pseudo cereal, the comprehensive exploration of buckwheat genotypes in the semi-tropical climatic region of India, reveals significant genetic variability among the genotypes for a range of biometrical features, underlining the potential for genetic improvement in this crop. Notably, traits such as days to maturity, and economic yield demonstrate substantial genetic potential for enhancement through targeted breeding programs, exhibiting relatively high genetic advancement values, indicating their potential for effective improvement through breeding programs. Disease resistance, as assessed by the percentage disease index (PDI) of chlorotic leaf spot and brown leaf spot, also reveals noteworthy scope for improvement, crucial for sustaining buckwheat cultivation in disease-prone regions. A correlation analysis uncovers intricate relationships between agronomic traits and disease parameters, with the observed positive correlation between plant height (PH) and economic yield (EY) suggesting that taller buckwheat plants may have a slight advantage in terms of yield, and the negative correlation between test weight (TW) and disease severity, both for chlorotic leaf spot (PDI CL) and brown leaf spot (PDI BL), underscores the potential for selecting genotypes with higher test weights as a means to enhance disease resistance. Identification of genotypes with low disease susceptibility offers promising avenues for disease-resistant buckwheat cultivation. Understanding the genetic parameters and disease dynamics presented in this study would be proved invaluable in developing resilient buckwheat varieties, ensuring food security, and promoting sustainable agriculture in the region opening doors to effective disease management strategies and improved crop productivity in buckwheat cultivation.

Phenotyping and Identification of Molecular Markers Associated with Leaf Rust Resistance in the Wheat Germplasm from Kazakhstan, CIMMYT and ICARDA.

Leaf rust (LR) is the most widespread disease of common wheat worldwide. In order to evaluate leaf rust resistance, 70 uncharacterized wheat cultivars and promising lines with unknown leaf rust resistance genes (Lr genes) were exposed to Kazakhstani Puccinia triticina (Pt) races at the seedling stage. Field tests were performed to characterize leaf rust responses at the adult plant growth stage in the 2020-2021 and 2021-2022 cropping seasons. The wheat collection showed phenotypic diversity when tested with two virulent races of Pt. Thirteen wheat genotypes (18.6%) showed high resistance at both seedling and adult plant stages. In most cases, breeding material originating from international nurseries showed higher resistance to LR. Nine Lr genes, viz. Lr9, Lr10, Lr19, Lr26, Lr28, Lr34, Lr37, Lr46, and Lr68, either singly or in combination, were identified in 47 genotypes. Known Lr genes were not detected in the remaining 23 genotypes. The most commonly identified resistance genes were Lr37 (17 cultivars), Lr34 (16 cultivars), and Lr46 (10 cultivars), while Lr19, Lr68, Lr26, and Lr28 were the least frequent. Four Lr genes were identified in Keremet and Hisorok, followed by three Lr genes in Aliya, Rasad, Reke, Mataj, Egana and Almaly/Obri. The molecular screening revealed twenty-nine carriers of a single Lr gene, ten carriers of two genes, six carriers of three genes, and two carriers of four genes. Most of these accessions showed a high and moderate level of APR (Adult plant resistance) and may be utilized for the incorporation of Lr genes in well-adapted wheat cultivars. The most effective combination was Lr37, Lr34, and Lr68, the carriers of which were characterized by a low disease susceptibility index. The obtained results will facilitate breeding programs for wheat resistance in Kazakhstan.

The status of spotted wolffish, Anarhichas minor: A commercially ready species for U.S. marine aquaculture?

AbstractThe requirements to rear spotted wolffish, Anarhichas minor, a cold water, demersal fish, native to the north Atlantic Ocean, have been developed over the past 25 years (since 1990s) and it now is commercially produced in one fish farm in Norway with additional plans for commercial development in the near future in Quebec, Canada. Spotted wolffish have numerous attributes that make them a desirable species to culture in the United States including, but not limited to: having a high value; desired by consumers and chefs; not supplied by U.S. or Canadian fisheries; an established broodstock available in neighboring Quebec; well‐developed hatchlings that do not require live feed; high rearing density tolerance; and low disease susceptibility. Here, we review the advancements made in broodstock management and spawning, egg incubation, juvenile rearing, and on‐growing of fish, as well as future research and development needs. Areas requiring further focus include reducing variability in gamete production; nutritional studies at all life stages; health expertise; genetic selection; and further refinement of standard operating procedures at the commercial level for all life‐stages. Given the state of advancement of wolffish cultivation and the existence of a commercial operation in Norway, we propose that spotted wolffish is commercially ready for production in the United States with the primary barrier being a steady source of eggs to supply emerging pilot‐scale or commercial operations.

Incidence and Severity of End-Splitting in Plantation-Grown Eucalyptus pellita F. Muell. in North Borneo

Eucalyptus pellita F. Muell. is currently the predominant tree species deployed for tree plantation establishment in some parts of Borneo, particularly Sabah state, Malaysia. Its low disease susceptibility, good growth and form, and desirable wood properties make E. pellita particularly suitable for plantation development in the wet tropical regions of south-east Asia. In spite the many positive traits, practical field observations indicate that the species is susceptible to end-splitting. There is some anecdotal evidence to suggest a genetic relationship with the incidence of end-split, although these observations were not statistically tested. This study evaluates the occurrence of end-splitting in five-year old plantation E. pellita in Sabah as affected by family and growth attributes. An existing progeny tree breeding trial, involving seeds that originated from Papua New Guinea, China, Vietnam, Australia, Sabah, and Sarawak with 106 families, was used to carry out the split assessment. Logs from the second thinning were cut into 2.2-m-long sections. The end splits were measured three days later; the incidence and severity of splitting were assessed at both the large and small ends of each log by using a designated split scoring system. The study shows that 99% of all log cross sections (per cut surface) experienced signs of splitting, with an average of 2.7 splits per cut surface. Overall, 54% of all splits were classed as ‘Three-Quarter Radial Splits’ while the occurrence of internal splits was negligible. Split severity showed a heritable and significant difference (h2 = 0.24 at p ≤ 0.05) among the family levels. Splitting was also significantly related to growth factors such as tree height and diameter at breast height (DBH). The findings suggest that end-splitting is caused by family–environment interactions. This offers the opportunity to improve the wood resource of E. pellita via breeding strategies.

Reduction of Ethanol Yield from Switchgrass Infected with Rust Caused by Puccinia emaculata

Switchgrass (Panicum virgatum) is an important biofuel crop candidate thought to have low disease susceptibility. As switchgrass production becomes more prevalent, monoculture and production fields in close proximity to one another may increase the spread and severity of diseases such as switchgrass rust caused by the pathogen Puccinia emaculata. The objective of this research was to examine the impact of rust on ethanol yield in switchgrass. In 2010 and 2012, naturally infected leaves from field-grown ‘Alamo’ and ‘Kanlow’ in Knoxville, TN (2010, 2012) and Crossville, TN (2012) were visually categorized as exhibiting low, medium, or high disease based on the degree of chlorosis and sporulation. P. emaculata was isolated from each disease range to confirm infection. Samples from 2010 were acid/heat pretreated and subjected to two runs of simultaneous saccharification and fermentation (SSF) with Saccharomyces cerevisiae D5A to measure ethanol yield. Near-infrared spectroscopy (NIRS) was used to estimate ethanol yield for 2012 samples. SSF and NIRS data were analyzed separately using ANOVA. Disease level effects were significant within both models (P < 0.05) and both models explained a large amount of variation in ETOH (SSF: R 2 = 0.99, NIRS: R 2 = 0.99). In the SSF dataset, ethanol was reduced by 35 % in samples exhibiting medium disease symptoms and by 55 % in samples exhibiting high disease symptoms. In the NIRS dataset, estimated ethanol was reduced by 10 % in samples exhibiting medium disease symptoms and by 21 % in samples exhibiting high disease symptoms. Results indicate that switchgrass rust will likely have a negative impact on ethanol yield in switchgrass grown as a biofuel crop.

Carrot cultivar response to foliage side trimming for suppression of Sclerotinia rot

Foliage side trimming opens the carrot canopy, permitting greater sunlight penetration and airflow. This prevents moisture build-up and creates unfavourable conditions for the development of common carrot pathogens such as Sclerotinia sclerotiorum (Lib.) de Bary. This study was carried out at the Agriculture and Agri-Food Canada Harrington Research Farm in the growing seasons of 2007, 2008 and 2009, to examine cultivar yield response to foliage side trimming and suppression of Sclerotinia rot of carrot (SRC). All plots were assessed for disease incidence at the time of trimming and again at harvest. As well, carrots were placed into storage at 10 °C for three months to assess the incidence of infected roots. Cultivars varied in yield and other biological parameters, including susceptibility to SRC. Across cultivars, side foliage trimming significantly reduced total and marketable yield by approximately 7.5 and 9.1%, respectively. Overall, side foliage trimming significantly reduced the number of petioles with SRC at both the September and harvest assessments. The incidence of stored roots with SRC was also significantly reduced by side foliage trimming in one year of the study. Disease management strategies for SRC could include selection of cultivars with low disease susceptibility and use of side foliage trimming to reduce disease incidence in susceptible cultivars that are grown for specific agronomic traits.

Life cycle analysis reveals higher agroecological benefits of organic and low-input apple production

Conventional agricultural systems depend on high inputs of fertilizers and toxic pesticides that are a threat for human health and the environment. Such issues are rapidly changing agriculture in Europe. As a consequence sustainable production systems are currently developed as safer alternatives, for instance organic and low-input systems use of mechanical and biological methods versus toxic substances. However, there is a lack of knowledge on the overall impact of these alternative systems on toxicity, energy use, and global warming, notably for perennial crops such as apple orchards, which require the control of many pests. Here we present the first analysis of the environmental impacts of nine apple orchard systems using life cycle analysis. We used data from a survey of apple orchard systems located in Southern France, covering 2006–2009. Conventional, low-input, and organic orchards were planted with three apple cultivars differing in their disease susceptibility, hence designing nine apple systems, with the Golden Delicious conventional system being considered as the reference. Our results show that low-input systems planted with low disease susceptibility Melrose cultivar decreased environmental impacts by 6–99 %. Organic systems had one of the highest impacts per mass unit due to low yields, but showed low impacts per area unit planted with low-susceptibility cultivars generally. Potential toxicity was decreased by 2–40 % for human, 71–82 % for aquatic life, and 97–99 % for terrestrial life using mechanical control versus toxic pesticides to control weeds and diseases.

Genetic Association Analysis of the Functional c.714T&gt;G Polymorphism and Mucosal Expression of Dectin-1 in Inflammatory Bowel Disease

BackgroundDectin-1 is a pattern recognition receptor (PRR) expressed by myeloid cells that specifically recognizes β-1,3 glucan, a polysaccharide and major component of the fungal cell wall. Upon activation, dectin-1 signaling converges, similar to NOD2, on the adaptor molecule CARD9 which is associated with inflammatory bowel disease (IBD). An early stop codon polymorphism (c.714T>G) in DECTIN-1 results in a loss-of-function (p.Y238X) and impaired cytokine responses, including TNF-α, interleukin (IL)-1β and IL-17 upon in vitro stimulation with Candida albicans or β-glucan. The aim of the present study was to test the hypothesis that the DECTIN-1 c.714T>G (p.Y238X) polymorphism is associated with lower disease susceptibility or severity in IBD and to investigate the level of dectin-1 expression in inflamed and non-inflamed colon tissue of IBD patients.MethodologyParaffin embedded tissue samples from non-inflamed and inflamed colon of IBD patients and from diverticulitis patients were immunohistochemically stained for dectin-1 and related to CD68 macrophage staining. Genomic DNA of IBD patients (778 patients with Crohn's disease and 759 patients with ulcerative colitis) and healthy controls (n = 772) was genotyped for the c.714T>G polymorphism and genotype-phenotype interactions were investigated.Principal FindingsIncreased expression of dectin-1 was observed in actively inflamed colon tissue, as compared to non-inflamed tissue of the same patients. Also an increase in dectin-1 expression was apparent in diverticulitis tissue. No statistically significant difference in DECTIN-1 c.714T>G allele frequencies was observed between IBD patients and healthy controls. Furthermore, no differences in clinical characteristics could be observed related to DECTIN-1 genotype, neither alone, nor stratified for NOD2 genotype.ConclusionsOur data demonstrate that dectin-1 expression is elevated on macrophages, neutrophils, and other immune cells involved in the inflammatory reaction in IBD. The DECTIN-1 c.714T>G polymorphism however, is not a major susceptibility factor for developing IBD.

Reactions of Sorghum Genotypes to Anthracnose and Grey Leaf Spot Diseases Under Sudan and Sahel Savanna Field Conditions of Nigeria

ABSTRACT Ten early- and 10 medium-maturing sorghum genotypes were evaluated for individual and multiple resistance to anthracnose and grey leaf spot in field trials carried out at Ajiwa (Sahel savanna) and Bagauda (Sudan savanna), Nigeria in the 1995, 1996 and 1997 wet seasons. Among the early-maturing genotypes, five were resistant to anthracnose and two resistant to grey leaf spot, while one genotype ICSV 901 NG had resistance to both. Among the medium-maturing, five genotypes were resistant to anthracnose and grey leaf spot while four of these genotypes, CGM 19/9-1-1, CEM 328/2-1-1-3, Sariasso 10 and Gaya early (local) had low disease scores for both diseases. Further, local landraces had low disease susceptibility and comparable high yields indicating the need to promote their use in areas where they are adapted to ensure sustainable sorghum production. The study shows the availability of sorghum genotypes with stable resistance to anthracnose and grey leaf spot within Nigeria.

Effect of pattern and severity of moisture-deficit stress on stalk-rot incidence in sorghum. II. Effect of source/sink relationships

Stalk-rot of grain sorghum [ Sorghum bicolor (L.) Moench] is most commonly associated with weakly parasitic root and stalk-rot fungi when the host plants are subjected to environmental stresses. The incidence of rots is generally more in high-grain-yield environments associated with high plant density or fertilizer application. The effects of time of occurrence and degree of moisture deficit stress (moisture stress) on grain and biomass yields, and the natural incidence of stalk-rots were studied. Stress during grain-filling had a greater effect on incidence of rots than stress at earlier stages. Grain-yield and disease incidence were differently affected by timing and severity of moisture stress. Stalk-rot incidence was most commonly and strongly associated with moisture stress at the terminal stage of growth. However, stress during panicle development induced changes in the sink size (grain number) or root-growth pattern, which in turn influenced both the timing and extent of stalk-rot incidence. The amount of biomass produced during the later part of the grain-filling period was positively correlated with lower disease susceptibility. The distribution index (i.e., the ratio of grain-yield to biomass produced after flowering) could be generally used to predict disease susceptibility. There were no simple correlations between biomass, grain-yield or yield components, and stalk-rot. Implications of these findings for sorghum production and for stalk-rot resistance screening are discussed.