Jiang Kai, Yang Zhimin, Sun Juan, Liu Huancheng, Chen Shenmiao, Zhao Yongzhuo, Xiong Wangdan, Lu Wenjie, Wang Zeng-Yu, Wu Xueli
College of Grassland Science, Qingdao Agricultural University, Qingdao, China.
College of Grassland Science, Nanjing Agricultural University, Nanjing, China.
Front Plant Sci. 2022 Sep 29;13:944894. doi: 10.3389/fpls.2022.944894. eCollection 2022.
Seashore paspalum is a halophytic, warm-season grass with wide applications. It is noted for its superior salt tolerance in saline environments; however, the nutritive value of seashore paspalum and the effect of salinity remains to be determined. Therefore, this study aimed to evaluate the relationship between agronomic traits and forage quality and identified the effects of short-term high-salt stress (1 week, 700 mM NaCl) on the growth and forage nutritive value of 16 ecotypes of seashore paspalum. The salt and cold tolerances of the seashore paspalum ecotypes were assessed based on the survival rate following long-term high-salt stress (7 weeks, 700 mM NaCl) and exposure to natural low temperature stress. There were significant genetic (ecotype-specific) effects on plant height, leaf-stem ratio, and survival rate of seashore paspalum following salt or low temperature stress. Plant height was significantly negatively correlated with the leaf-stem ratio ( = -0.63, <0.01), but the heights and leaf-stem ratios were not significantly correlated with the fresh weight (FW) and dry weight (DW) of the shoots. High salinity decreased the FW and DW of the shoots by 50.6% and 23.6%, respectively, on average. Seashore paspalum exhibited outstanding salt tolerance and forage quality at high salinity. The survival rate of the different ecotypes of seashore paspalum varied from 6.5% to 49.0% following treatment with 700 mM NaCl for 7 weeks. The crude protein (CP) content of the control and treatment groups (700 mM NaCl) was 17.4% and 19.3%, respectively, of the DW on average, and the CP content of most ecotypes was not significantly influenced by high salinity. The average ether extract (EE) content ranged from 4.6% to 4.4% of the DW under control and saline conditions, respectively, indicating that the influence was not significant. The neutral detergent fiber (NDF) and acid detergent fiber (ADF) contents of the control group were 57.4% and 29.8%, respectively, of the DW on average. Salt stress reduced the content of NDF and ADF to 50.2% and 25.9%, respectively, of the DW on average. Altogether, the results demonstrated that stress did not have any significant effects on the CP and EE content of most ecotypes, but reduced the NDF and ADF content and improved relative feed value (RFV). The results obtained herein support the notion that seashore paspalum is a good candidate for improving the forage potential of saline soils and can provide useful guidelines for livestock producers.
海滨雀稗是一种盐生暖季型草，应用广泛。它以在盐渍环境中具有卓越的耐盐性而闻名；然而，海滨雀稗的营养价值以及盐分的影响仍有待确定。因此，本研究旨在评估农艺性状与饲草品质之间的关系，并确定短期高盐胁迫（1周，700 mM NaCl）对16个海滨雀稗生态型生长和饲草营养价值的影响。基于长期高盐胁迫（7周，700 mM NaCl）后的存活率以及自然低温胁迫下的存活率，对海滨雀稗生态型的耐盐性和耐寒性进行了评估。盐胁迫或低温胁迫后，海滨雀稗的株高、叶茎比和存活率存在显著的遗传（生态型特异性）效应。株高与叶茎比显著负相关（r = -0.63，P < 0.01），但株高和叶茎比与地上部鲜重（FW）和干重（DW）无显著相关性。高盐度使地上部FW和DW平均分别降低了50.6%和23.6%。海滨雀稗在高盐度下表现出优异的耐盐性和饲草品质。用700 mM NaCl处理7周后，不同海滨雀稗生态型的存活率在6.5%至49.0%之间。对照组和处理组（700 mM NaCl）的粗蛋白（CP）含量平均分别为DW的17.4%和19.3%，大多数生态型的CP含量不受高盐度的显著影响。对照组和盐处理条件下，平均乙醚提取物（EE）含量分别为DW的4.6%至4.4%，表明影响不显著。对照组中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量平均分别为DW的57.4%和29.8%。盐胁迫使NDF和ADF含量平均分别降至DW的50.2%和25.9%。总体而言，结果表明胁迫对大多数生态型的CP和EE含量没有显著影响，但降低了NDF和ADF含量并提高了相对饲用价值（RFV）。本文获得的结果支持了海滨雀稗是提高盐渍土壤饲草潜力的良好候选植物这一观点，并可为畜牧生产者提供有用的指导。
