The successful screening and evaluation of salt-tolerant germplasm at the germination and seedling stages is of great importance for promoting the breeding of wheat varieties with salt tolerance. In this study, 70 wheat varieties bred in different regions were evaluated for salt tolerance through hydroponic exposure to different concentrations of salt. The relative water absorption, water absorption rate, dehiscence rate, germination rate, and germination index of seeds, and plant height, root length, stem diameter, and biomass of seedlings were determined at the germination and seedling stages of wheat, and the salt tolerance was identified and evaluated using multivariate statistical analysis. The germination ability and seedling growth potential of wheat germplasms decreased with the aggravation of salt stress. Based on the comprehensive salt tolerance index at the germination stage, our study identified 35 varieties to be salt-tolerant. There were nine varieties further screened for having strong salt tolerance according to the comprehensive salt tolerance index at the germination and seedling stages. SN41, Emam, YN301, and JM262 were superior in salt-tolerance, and YM39, LM30, JM60, YN999, and SD29 were salt-tolerant. Our study suggests that the biomass of seedlings can be used as a key parameter for assessing wheat germplasm’s ability to withstand salt. Our results can provide some basic materials for cultivating new germplasm with salt tolerance and excavating the related genes of wheat.

Cotton growth and yield are severely affected by abiotic stress worldwide. Mepiquate chloride (MC) and melatonin (MT) enhance crop growth and yield by reducing the negative effects of abiotic stress on various crops. Numerous studies have shown the pivotal role of MC and MT in regulating agricultural growth and yield. Nevertheless, an in-depth review of the prominent performance of these two hormones in controlling plant morpho-physiological activity and yield in cotton under abiotic stress still needs to be documented. This review highlights the effects of MC and MT on cotton morpho-physiological and biochemical activities; their biosynthetic, signaling, and transduction pathways; and yield under abiotic stress. Furthermore, we also describe some genes whose expressions are affected by these hormones when cotton plants are exposed to abiotic stress. The present review demonstrates that MC and MT alleviate the negative effects of abiotic stress in cotton and increase yield by improving its morpho-physiological and biochemical activities, such as cell enlargement; net photosynthesis activity; cytokinin contents; and the expression of antioxidant enzymes such as catalase, peroxidase, and superoxide dismutase. MT delays the expression of NCED1 and NCED2 genes involved in leaf senescence by decreasing the expression of ABA-biosynthesis genes and increasing the expression of the GhYUC5, GhGA3ox2, and GhIPT2 genes involved in indole-3-acetic acid, gibberellin, and cytokinin biosynthesis. Likewise, MC promotes lateral root formation by activating GA20x genes involved in gibberellin catabolism. Overall, MC and MT improve cotton’s physiological activity and antioxidant capacity and, as a result, improve the ability of the plant to resist abiotic stress. The main purpose of this review is to present an in-depth analysis of the performance of MC and MT under abiotic stress, which might help to better understand how these two hormones regulate cotton growth and productivity.

The forage shortage is more aggravating than ever before, with husbandry development accelerating and meat and dairy product demand increasing. Salinized soils are important reserve land encouraged to be used for forage production in China. However, the salt-tolerant cultivation techniques for forage crops are still inadequate. Therefore, a field experiment was conducted to study the effects of the mixed cropping ratio of oat and alfalfa on plant growth and physiological traits, forage yield, and forage quality in saline soils. Oat (Avena sativa L.) variety of Canadian Monopoly and alfalfa variety of WL525HQ were used, and five mixed cropping ratios (T1 = 100% oat + 0% alfalfa, CK, T2 = 75% oat + 25% alfalfa, T3 = 50% oat + 50% alfalfa, T4 = 25% oat + 75% alfalfa, and T5 = 0% oat + 100% alfalfa) were evaluated. The results showed that plant height, chlorophyll, soluble sugar, starch, antioxidant enzymes, and crude fat were increased firstly and then decreased prominently with decreased oats and increased alfalfa sowing rate; the maximum values showed under T2 but the minimum value under T5 at evaluated growth periods. On the contrary, malondialdehyde and acid detergent fiber were significantly decreased and then increased; the lowest contents were recorded under T2 and highest under T5. Furthermore, the relative growth rate, forage yield, neutral detergent fiber, and crude ash were decreased prominently with decreased oats and increased alfalfa sowing rate, and the highest and lowest values showed under T1 and T5, respectively. Oppositely, the contents of sucrose, proline, N, P, K, relative feeding value, and crude protein were all increased, with the highest contents generated under T2 and the lowest under T1. On the whole, the mixed cropping treatment of T2 showed the best performance in improving both biomass yield and forage quality by enhanced antioxidant enzyme activity, osmotic regulatory substances, and nutrient uptake and utilization. Therefore, this study indicates that 75% oat mixed cropping with 25% alfalfa can be recommended as a salt-tolerant cultivation technique for forage high-yield and high-quality production in moderately saline soil.

The vast expanse of saline-alkali land in China represents a significant reserve of land resources for agricultural development. Therefore, it is essential to explore the saline-alkali tolerance of crops, the benefits of saline-alkali soil improvement, and their carbon sequestration potential. This study utilized the sorghum variety Jinliang 211 as the experimental material, conducting trials in saline-alkali woodland. A control and four different treatments combining organic fertilizers and soil amendments were established to investigate the effects of these mixtures on sorghum growth, antioxidant enzyme activity, soil improvement, and carbon sequestration characteristics. The results indicated that the combined application of organic fertilizer and rice husk biochar could enhance the salt tolerance of Jinliang 211, improve soil quality, and increase soil carbon sequestration capacity. Among the measured plant indicators, the T2 treatment (combined application of organic fertilizer and rice husk biochar) resulted in the highest dry matter accumulation, which was 68.4% higher than the control. Concurrently, the activities of antioxidant enzymes such as SOD, POD, and CAT significantly increased during the jointing stage post-treatment, with the highest enzyme activities observed in the T2 treatment. Regarding soil indicators, the soil organic carbon content initially increased and then decreased, with the T2 treatment showing the highest soil organic carbon content, 9.8% higher than the control. The soil pH initially decreased and then increased, with the T2 treatment exhibiting the lowest soil pH, 5.6% lower than the control. Importantly, the T2 treatment demonstrated the most pronounced “net carbon sink” characteristics in the soil. In summary, the T2 mixed treatment performed the best in enhancing sorghum antioxidant enzyme activity, increasing dry matter accumulation, and strengthening the carbon sequestration characteristics of saline-alkali soil.