Tang Kang, Liu Dengwang, Liu Na, Zeng Ningbo, Wang Jianguo, Li Lin, Luo Zinan
College of Agriculture, Hunan Agricultural University, Changsha, Hunan, China.
Arid Land Crop Research Institute, Hunan Agricultural University, Changsha, Hunan, China.
Front Plant Sci. 2023 Aug 21;14:1250064. doi: 10.3389/fpls.2023.1250064. eCollection 2023.
Peanut yield in southern China is usually limited by calcium deficiency in soil. Most previous studies have found that small-seed varieties showed higher tolerance than large-seed varieties (e.g. Virginia type) under calcium deficiency, however, our preliminary research found that sensitive varieties also existed in small-seed counterparts. Few studies have been conducted to characterize low-calcium tolerance among small-seed germplasms with genetic diversity, and the differences in physiological characteristics between sensitive and tolerant varieties has not been reported yet. Thus, in order to better understand such differences, the current study firstly collected and characterized a diversity germplasm panel consisting of 50 small-seed peanut genotypes a 2-year field trial, followed by the physiological characterization in sensitive (HN032) and tolerant (HN035) peanut genotypes under calcium deficiency. As a result, the adverse effects brought by calcium deficiency on calcium uptake and distribution in HN032 was much larger than HN035. In details, calcium uptake in the aboveground part (leaves and stems) was reduced by 16.17% and 33.66%, while in the underground part (roots and pods), it was reduced by 13.69% and 68.09% under calcium deficiency for HN035 and HN032, respectively; The calcium distribution rate in the pods of HN035 was 2.74 times higher than HN032. The utilization efficiency of calcium in the pods of HN035 was 1.68 and 1.37 times than that of HN032 under calcium deficiency and sufficiency, respectively. In addition, under calcium deficiency conditions, the activities of antioxidant enzymes SOD, POD, and CAT, as well as the MDA content, were significantly increased in the leaves of HN032, peanut yield was significantly reduced by 22.75%. However, there were no significant changes in the activities of antioxidant enzymes, MDA content, and peanut yield in HN035. Therefore, higher calcium absorption and utilization efficiency may be the key factors maintaining peanut yield in calcium-deficient conditions for tolerant genotypes. This study lays a solid foundation for selecting low-calcium tolerant varieties in future peanut breeding.
中国南方的花生产量通常受土壤缺钙的限制。以往大多数研究发现，在缺钙条件下小种子品种比大种子品种（如弗吉尼亚型）表现出更高的耐受性，然而，我们的初步研究发现小种子品种中也存在敏感品种。很少有研究对具有遗传多样性的小种子种质的耐低钙性进行表征，且敏感品种和耐受品种之间的生理特征差异尚未见报道。因此，为了更好地了解这些差异，本研究首先收集并表征了一个由50个小种子花生基因型组成的多样化种质库，并进行了为期2年的田间试验，随后对缺钙条件下敏感（HN032）和耐受（HN035）花生基因型进行了生理表征。结果表明，缺钙对HN032钙吸收和分配带来的不利影响远大于HN035。具体而言，缺钙时，HN035地上部分（叶和茎）的钙吸收分别减少了16.17%和33.66%，而地下部分（根和荚果）分别减少了13.69%和68.09%；HN035荚果中的钙分配率比HN032高2.74倍。缺钙和钙充足条件下，HN035荚果中钙的利用效率分别是HN032的1.68倍和1.37倍。此外，在缺钙条件下，HN032叶片中抗氧化酶SOD、POD和CAT的活性以及MDA含量显著增加，花生产量显著降低22.75%。然而，HN035中抗氧化酶活性、MDA含量和花生产量没有显著变化。因此，更高的钙吸收和利用效率可能是耐受基因型在缺钙条件下维持花生产量的关键因素。本研究为未来花生育种中筛选耐低钙品种奠定了坚实基础。
