The sense and antisense fragments of the soluble starch synthase (SSIII) gene and the intron fragment of somatic embryogenesis receptor-like kinase (SERK1) gene were cloned from potato using PCR techniques. The RNAi plant expression vectors pBI-SSIII-RNAi and pBIC-SSIII-RNAi were constructed which containing fusion fragment of “sense fragment-intron-antisense fragment” driven by the constitutive expression promoter CaMV 35S and the tuber-specific expression promoter CIPP, respectively. The putative transgenic plants of potato cultivars Kexin-1 and Kexin-4 were obtained using Agrobacterium-mediated transformation method. PCR assay showed that the interference fragment of SSIII gene was integrated into potato genome. The RT-PCR analysis showed that the expression of SSIII gene was repressed apparently on the transcription level. Starch granules of the transgenic potato plants were different in morphology and became cracked in starch granule centre compared with the non-transgenic control plants. The amylose content of starch was increased by 2.68-29.05%, amylopectin to amylose ratio of starch had declined significantly, and the phosphorus content of the starch of the transgenic plants was reduced 9.94-58.36% compared with control plants. The results could provide certain foundation for improvement of potato starch quality.

Drought and salinity are the most important abiotic stresses that affect the normal growth and development of plants. Glycine betaine is one of the most important osmolytes present in higher plants that enable them to cope with environmental stresses through osmotic adjustment. In this study, a betaine aldehyde dehydrogenase (BADH) gene from spinach under the control of the stress-induced promoter rd29A from Arabidopsis thaliana was introduced into potato cultivar Gannongshu 2 by the Agrobacterium tumefaciens system. Putative transgenic plants were confirmed by Southern blot analysis. Northern hybridization analysis demonstrated that expression of BADH gene was induced by drought and NaCl stress in the transgenic potato plants. The BADH activity in the transgenic potato plants was between 10.8 and 11.7 U. There was a negative relationship (y = −2.2083x + 43.329, r = 0.9495) between BADH activity and the relative electrical conductivity of the transgenic potato plant leaves. Plant height increased by 0.4–0.9 cm and fresh weight per plant increased by 17–29% for the transgenic potato plants under NaCl and polyethylene glycol stresses compared with the control potato plants. These results indicated that the ability of transgenic plants to tolerate drought and salt was increased when their BADH activity was increased.

Potato is one of the most important crops in the production of starch.Soluble starch synthase SSⅢ is the main activity composition of soluble starch synthase.Therefore,it is possible to alter starch quality and quantity and investigate function of SSⅢ gene in potato starch synthesis via genetic engineering methods.Soluble starch synthase SSⅢ gene of RNA interference expression vectors driven by the constitutive expression promoter CaMV 35S were introduced into two potato cultivars Kexin1 and Kexin4 by Agrobacterium-mediated transformation method.Then 65 kanamycin-resistant plants were obtained from the resistant kanamycin.PCR detection showed that the interference fragment of SSⅢ gene was integrated into potato genome.RT-PCR analysis showed that the expression of SSⅢ gene was repressed apparently on the transcription level.These results should be pave the way for improvement of potato starch quality.

According to the conservative property of miRNAs in plant,a total of 32 novel miRNAs were identified from potato following a range of filtering criteria by using previously deposited miRNA sequences from Arabidopsis thaliana,Oryza sativa and other plant species to blast potato expressed sequence tags (EST),genomic survey sequence (GSS) and nucleotide databases,and removing the protein coding genes by on line software blastx.All the potential miRNA precursors could be folded into the typical secondary structure of miRNA family.Using these miRNAs sequences,100 target genes were identified by blasting the databases of cording protein using on line software miRU and miRU2.These genes encode protein involved in growth and development,metabolism,signal transduction,transcriptional regulation and stress responses.

马铃薯块茎的休眠和发芽对于马铃薯栽培、贮藏保鲜和加工等具有十分重要的意义.本研究以25℃室温条件下贮藏90 d后的转正义和反义无机焦磷酸酶(PPase)基因马铃薯Favorita的块茎为材料,对贮藏块茎的PPase活性和及Pi、可溶性糖、淀粉、蛋白质含量进行了测定,以探讨PPase基因对马铃薯相关休眠生理特性的影响.结果表明,与对照相比,转正义PPase基因的两个株系F-2-1和F-2-4块茎中的PPase活性、Pi含量和可溶性糖含量增加、淀粉含量和蛋白质含量降低,且与对照相比均达到极显著水平(只有F-2-4淀粉含量与对照相比无显著性变化);转反义PPase基因的两个株系F-1-1和F-1-2块茎中PPase活性、Pi含量和可溶性糖含量降低、淀粉含量增加,与对照相比均达到极显著性水平,而蛋白质含量与对照相比无显著性变化.

试验表明：采用高温(33-35℃)预处理甘薯茎尖组织作为外植体并以MS为基本培养基进行组织培养,可提高成苗率。同时对添加不同生长调节剂培养基的3个品种甘薯茎段进行分生组织培养和脱毒苗快速繁殖研究。结果表明：IAA和NAA对甘薯脱毒苗的生长都有促进作用，但在含有6-BA2.18μmol/L +GA328.31μmol/L的MS培养基中，2.61μmol/L的NAA对甘薯脱毒苗的快繁更有利。