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Sesame is an important and specific oilseed crop with high quality. Here, we systematically investigated the relationships between plant seed yield (PSY) and nine related traits in 369 sesame core accessions under five environments. The PSY and related traits had general heritability ranging from 14% for PSY to 72% for height to the first capsule (FCH) and final flowering stage (FFS). Correlation analysis suggested that seven yield-related traits, including capsule number per plant (CNP, r = 0.67), capsule stem length (CSL, 0.56), thousand-seed weight (TSW, 0.26), plant height (PH, 0.24), FFS (0.17), initial flowering stage (IFS, − 0.16) and FCH (− 0.14) were the key factors associated with seed yield in sesame (P < 0.01). For the uniculm and branching groups, CNP, CSL, and TSW were the common key factors. Path analysis showed similar direct effects of these key factors on PSY. Association mapping identified 13 simple sequence repeat (SSR) markers significantly associated with the nine seed yield-related traits (P < 0.001). Among these, three SSR markers were repeatedly detected in two environments. Marker Hs635 was associated with the seed number per capsule (SNC). Hs345 was associated with the CNP. Hs618 was associated with the IFS in uniculm accessions. These results provide insights into the traits that influence PSY and their genetics in sesame. [ABSTRACT FROM AUTHOR]

Key message: A 4.43-Kb structural variation in the sesame genome results in the deletion of the Siofp1 gene and induces the long capsule length trait. Capsule length (CL) has a positive effect on seed weight and yield in various agronomically important species; however, the molecular mechanism underlying long capsule trait regulation in sesame remains unknown. The inheritance analysis showed that long capsule traits (CL > 4.0 cm) were dominant over normal length (average CL = 3.0 cm) and were controlled by a single gene pair. Association mapping with a RIL population and 259 natural sesame germplasm accessions indicated that the target interval was 52,830–730,961 bp of SiChr.10 in sesame. Meanwhile, the structural variation (SV) of the association mapping revealed that only SV_414325 on chromosome 10 was significantly associated with the CL trait, with a P value of 1.1135E−19. SV_414325 represents a 4430-bp deletion from 414,325 to 418,756 bp on SiChr.10, covering Sindi_2155000 (named SiOFP1). In the normal length type, Siofp1 encodes 411 amino acids of the ovate family proteins and is highly expressed in the leaf, stem, bud, and capsule tissues of sesame. In accordance with the transcriptional repressor character, Siofp1 overexpression in transgenic Arabidopsis (T0 and T1 generations) induced a 25–39% greater shortening of silique length than the wild type (P < 0.05), as well as round cauline leaves and short carpels. These results confirm that SiOFP1 plays a key role in regulating CL trait in sesame and other flowering plants. These findings provide a theoretical and material basis for sesame capsule development and high-yield breeding research. [ABSTRACT FROM AUTHOR]

The germplasm of the genus Nicotiana contains more than 5,000 accessions and plays an important role in modern biological research. Tobacco can be used as a model system to develop methodologies for plant transformation and for investigating gene function. In order to develop the study of Nicotiana, a large quantity of data on germplasm, sequences, molecular markers and genetically modified tobacco was required for in-depth and systematic collation and research. It became necessary to establish a special database for tobacco genetics and breeding. The tobacco genetics and breeding (TGB, http://yancao.sdau.edu.cn/tgb) database was developed with the aim of bringing together tobacco genetics and breeding. The database has three main features: (1) a materials database with information on 1,472 Nicotiana germplasm accessions, as well as updated genomic and expressed sequence tag (EST) data available from the public database; (2) a molecular markers database containing a total of 12,388 potential intron polymorphisms 10,551 EST-simple sequence repeat (EST-SSR) and 66,297 genomic-SSR markers; and (3) an applications database with genetic maps and some genetically modified studies in tobacco. The TGB database also makes Basic Local Alignment Search Tool and primer designing tools publicly available. As far as can be ascertained, the TGB database is the first tobacco genetics and breeding database to be created, and all this comprehensive information will aid basic research into Nicotiana and other related plants. It will serve as an excellent resource for the online tobacco research community. [ABSTRACT FROM AUTHOR]