Seed priming with selenite enhances germination and seedling growth of Sorghum [Sorghum bicolor (L.) Moench] under salt stress

Justify that the use of selenium has been shown to promote seed germination and seedling growth of some crops under salt stress but the physiological mechanisms in sorghum remain poorly understood. Herein, grain sorghum [Sorghum bicolor (L.) Moench] variety Jinza 2002 was used to explore the effects and mechanisms of seed priming with 25 μmol/L sodium selenite [Se(IV)] on seed germination, seedling growth, antioxidant enzyme activity and osmotic regulatory substances under 120 mmol/L NaCl. The results showed that soaking sorghum seeds in Se(IV) effectively alleviated the harm of salt stress. Compared with the Na group, Se(IV) application increased germination percentage (by 23.8%), while facilitating the elongation of radicles (by 4.2%) and plumules (by 18.4%) under salt stress. Salt-stressed seedlings showed increased levels of leaf chlorophyll, soluble sugar, soluble protein and proline contents, and antioxidant enzyme activities, as well as root activity, and total biomass following Se(IV) application, along with decreased relative electrical conductivity and malondialdehyde content in the leaves. Findings of this study indicate that seed priming with Se(IV) facilitates sorghum seed germination and seedling growth under salt stress by improving root activity, enhancing leaf photosynthesis and antioxidant responses, and reducing cell membrane damage

Effects of Different Organic Fertilizer Substitutions for Chemical Nitrogen Fertilizer on Soil Fertility and Nitrogen Use Efficiency of Foxtail Millet

Conventional fertilizer management can destroy the structure of soil. Replacing chemical fertilizers with organic fertilizers can improve soil quality and nitrogen use efficiency. We aimed to study the effects of organic fertilizer substitutions for chemical nitrogen fertilizer on soil fertility and nitrogen use efficiency in order to clarify the effectiveness of the available nutrient management measures in improving soil quality and increasing foxtail millet yield. A field experiment was carried out over two consecutive years, and a total of six treatments were set up: no fertilizer (CK), chemical nitrogen fertilizer alone (N), the substitution of 25% of chemical nitrogen fertilizer with bio-organic fertilizer (N25A1), the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure (N25B1), the substitution of 50% of chemical nitrogen fertilizer with bio-organic fertilizer (N50A2), and the substitution of 50% of chemical nitrogen fertilizer with fermented mealworm manure (N50B2). The results of this study show the following: (1) Compared with chemical nitrogen fertilizer, the substitution of organic fertilizer for nitrogen fertilizer reduced the bulk density and solid phase of the soil, and it increased the total porosity, water content, liquid phase, and gas phase of the soil. (2) Compared with nitrogen fertilizer, the use of an organic fertilizer increased the contents of nitrate nitrogen, ammonium nitrogen, and total nitrogen in the soil by 13.59~52.56%, 4.47~18.27%, and 4.40~12.09%, respectively. The content of alkaline nitrogen increased by 1.70~32.37%, and the contents of soil available potassium, available phosphorus, and organic matter also increased. (3) The activities of sucrase, urease, glutaminase, and asparaginase were improved by replacing chemical nitrogen fertilizer with organic fertilizer. The N25 treatments performed better than the N50 treatments, and fermented mealworm manure performed better than biological organic fertilizer. (4) A moderate application of organic fertilizer (N25) can increase the grain yield, ear weight, grain weight, and 1000-grain weight of foxtail millet, whereas excessive application of organic fertilizer (N50) can reduce foxtail millet yield. (5) Replacing chemical nitrogen fertilizer with organic fertilizer can improve the agronomic use efficiency, physiological efficiency, biased productivity, harvest index, and apparent use efficiency of nitrogen fertilizer. In this study, the substitution of 25% of chemical nitrogen fertilizer with fermented mealworm manure was the best combination for restoring crop productivity and soil quality

The Identification of a Yield-Related Gene Controlling Multiple Traits Using GWAS in Sorghum (<i>Sorghum bicolor</i> L.)

Sorghum bicolor (L.) is one of the oldest crops cultivated by human beings which has been used in food and wine making. To understand the genetic diversity of sorghum breeding resources and further guide molecular-marker-assisted breeding, six yield-related traits were analyzed for 214 sorghum germplasm from all over the world, and 2,811,016 single-nucleotide polymorphisms (SNPs) markers were produced by resequencing these germplasms. After controlling Q and K, QTLs were found to be related to the traits using three algorisms. Interestingly, an important QTL was found which may affect multiple traits in this study. It was the most likely candidate gene for the gene SORBI_3008G116500, which was a homolog of Arabidopsis thaliana gene-VIP5 found by analyzing the annotation of the gene in the LD block. The haplotype analysis showed that the SORBI_3008G116500hap3 was the elite haplotype, and it only existed in Chinese germplasms. The traits were proven to be more associated with the SNPs of the SORBI_3008G116500 promoter through gene association studies. Overall, the QTLs and the genes identified in this study would benefit molecular-assisted yield breeding in sorghum