花生是重要的油料作物，培育高油品种是花生育种的主要目标之一。研究表明，干旱胁迫下花生叶片渗透压与其籽仁含油量呈显著负相关。基于这一原理，我们创建了利用离体诱变和渗透压定向筛选培育高油花生新品种的有效方法。以花生品种花育20号的种子胚小叶为外植体，平阳霉素(PYM)为诱变剂，羟脯氨酸(HYP)为渗透压调节剂进行离体诱变和定向筛选，最终获得15株HYP耐性再生植株。每个再生植株均有含油量 >55%的后代（而花育20号含油量为49.5%）。从HYP耐性植株后代中培育出3个高产高油花生新品种，宇花4号、宇花9号、宇花14号，含油量分别为57.7%、61.1%、59.3%。结果表明，PYM离体诱变后进行HYP离体定向筛选，是培育高油花生品种的有效途径。

Phosphoenolpyruvate carboxylase (PEPC; EC 4.1.1.31) catalyses phosphoenolpyruvate (PEP) to yield oxaloacetate, which is involved in protein biosynthesis. Pyruvate kinase (PK; EC 2.7.1.40) catalyzes PEP to yield pyruvate, which is involved in fatty acid synthesis. In this study, five PEPC genes (AhPEPC1, AhPEPC2, AhPEPC3, AhPEPC4, and AhPEPC5) from peanut have been cloned. Using a quantitative real-time RT-PCR approach, the expression pattern of each gene was monitored during the seed development of four peanut varieties (E11, Hebeigaoyou, Naihan 1, and Huayu 26). It was found that these five genes shared similar expression behaviors over the developmental stages of E11 with high expression levels at 30 and 40 d after pegging (DAP); whereas these five genes showed irregular expression patterns during the seed development of Hebeigaoyou. In Naihan 1 and Huayu 26, the expression levels of the five genes remained relatively high in the first stage. The PEPC activity was monitored during the seed development of four peanut varieties and seed oil content was also characterized during whole period of seed development. The PEPC activity followed the oil accumulation pattern during the early stages of development but they showed a significantly negative correlation thereafter. These results suggested that PEPC may play an important role in lipid accumulation during the seed development of four peanut varieties tested.