Distinguishing among commercial varieties or accessions in a germplasm repository presents considerable challenges when dealing with common crops or large collections. In the genus Pisum L. the third intron of the gene STAYGREEN (SGR), responsible for the green/yellow cotyledon variation, contains a complex of repeat sequences that display considerable indel and single nucleotide (SNP) polymorphism. In a sample of 137 Pisum L. accessions obtained from various germplasm collections 76 alleles were identified, ranging from about 600 to 1500 nucleotides in length. In most cases alleles differed by insertion/deletion (indel) polymorphisms in addition to single base changes. The amplicon was particularly useful for distinguishing wild accessions (those with dehiscent pods and dormant seeds). Among the 51 P. sativum L. accessions examined with a definite wild phenotype there were 44 SGR alleles. When this allelic variation was combined with location data for the wild accessions, each allele could be assigned a unique geographical location. Similarly, of the 10 P. fulvum Sibth. & Sm. accessions analyzed, only a group of three had the same allele, two of which are known to be replicates. We were able to confirm the identities of several P. sativum accessions from different germplasm collections, as well as identifying two cases where supposedly synonymous accessions gave different intron sequences. In addition, a group of wild pea accessions from Greece, Sicily, and Portugal exhibited a unique repeat sequence not found in any other wild accession, suggesting that these accessions constitute a distinct lineage. The rate of nucleotide site variation in this fragment of the SGR locus was found to be about 2.22 × 10^–8 substitutions per site per year. This value is similar to those found for many other sequences in herbaceous papilionoid tribes, although it is at the faster end of the distribution of herbaceous legume substitution rates. We propose that both a fast substitution rate as well as the formation and rearrangement of indels have contributed to the high level of variation we detected at SGR. This PCR product should prove valuable in the identification of Pisum accessions, for quality control operations in germplasm repositories, and for exploring the evolutionary relationships within the genus.

在处理普通作物或大宗收藏品时，在种质资源库中区分商业品种或种质提出了相当大的挑战。在豌豆属（Pisum L. ）中，STAYGREEN（SGR）基因的第三个内含子负责绿色/黄色子叶的变异，包含复杂的重复序列，这些重复序列表现出相当大的indel和单核苷酸（SNP）多态性。在137 Pisum的样本中从各种种质收集物中获得的L.种质被鉴定出76个等位基因，其长度为约600至1500个核苷酸。在大多数情况下，除单碱基改变外，等位基因的差异还在于插入/缺失（插入/缺失）多态性。扩增子对于区分野生种（带裂果荚和休眠种子的种）特别有用。在51 P中。用确定的野生表型检查的无花苜蓿种质中有44个SGR等位基因。当将该等位基因变异与野生种的位置数据结合在一起时，可以为每个等位基因分配一个唯一的地理位置。同样地，在10个P.fulvum中西伯斯 ＆Sm。对经过分析的种质，只有三个一组具有相同的等位基因，其中两个已知是重复的。我们能够确认几个P的身份。来自不同种质集合的无性系种质，以及鉴定据称同义种质提供不同内含子序列的两种情况。另外，来自希腊，西西里岛和葡萄牙的一组野生豌豆种质表现出独特的重复序列，这在任何其他野生种质中均未发现，表明这些种质构成了独特的谱系。发现该SGR基因座片段中核苷酸位点变异的速率约为2.22×10 ^–8每个站点每年的替换次数。该值与在草食性乳头类动物部落中许多其他序列所发现的值相似，尽管该值位于草食性豆类替代率分布的较快端。我们认为快速替代率以及插入缺失的形成和重排都有助于我们在SGR上检测到高水平的变异。该PCR产物在鉴定Pisum品系，种质库中的质量控制操作以及探索属内的进化关系方面应被证明是有价值的。