江苏省优良食味粳稻的遗传与育种研究

为了培育适合在江苏种植的优良食味粳稻品种,以优良食味为主攻目标,对江苏省优质、抗病、高产粳稻品种的遗传基础开展了系统研究。通过关联分析,研究稻米蒸煮品质、营养品质与食味品质的关系,明确直链淀粉含量是影响食味品质的关键性状。直链淀粉含量为10%~14%的半糯米米饭表面光泽透亮、质地柔软、富有弹性,综合了糯米的柔软性和粳米的弹性,冷饭不硬,食味品质极佳,符合长三角地区人们喜食柔软香型粳米的口感需求。筛选出直链淀粉含量在10%左右、含有低直链淀粉含量基因Wx^(mp)的日本半糯粳稻品种“关东194”作为食味品质改良的核心种质。开发Wx^(mp)基因的分子标记,结合利用与抗病、高产相关基因紧密连锁的分子标记,开展优良食味、抗病、高产粳稻聚合育种。育成适合江苏省不同稻区种植的南粳46、南粳5055、南粳9108和南粳5718等优良食味粳稻系列新品种通过审定,形成了覆盖江苏省不同稻区的优良食味粳稻品种布局,累计推广面积超过533万公顷,有力地促进了江苏省及周边地区优质稻米产业的发展,为水稻产业供给侧结构调整,提质增效,保障粮食安全作出了重要贡献。

An experimental study on the choked flow characteristics of CO_(2) pipelines in various phases

High pressure pipeline transportation has been an established technology for economically transporting large amounts of CO_(2).However,there are still issues and associated risks that have to be effectively addressed and adequately understood.It is well known that a strong JouleThomson Cooling effect can occur when pressurized CO_(2) flows through a choke valve.Thus,to investigate the choking characteristics especially the temperature drop of high pressure CO_(2),a new laboratory scale experimental setup(total length of 14.85 m and the inner diameter of 15 mm)was constructed.Steady choked flow and transient choked flow tests were carried out respectively for pressurized CO_(2) in various initial phases.The phase transitions and temperature drop characteristics were then studied following the choked flow and the results show that the phase transitions in steady choked flow differs significantly from that in transient choked flow.For transient choked flow of various initial phases,all the flows downstream would transfer from single phase to gas-liquid twophase flow.Furthermore,the effect of water on transient choked flow of supercritical CO_(2) pipeline was investigated,and the phenomena of solid particles deposition was captured which was paramount importance of ensuring the safety operation of CO_(2)pipelines when throttling by the choke valves.

Effects of soluble starch synthase genes on eating and cooking quality in semi waxy japonica rice with Wx^(mp)

The purpose of this study is to reveal the genetic mechanism of the variation of amylose content among different semi waxy or glutinous japonica rice in the background of Wxmp gene.Sixty-four semi waxy lines derived from the hybrid progenies of Wujing 13 and Milky Princess(Kantou 194)with polymorphism in soluble starch synthase gene SSIIa(SSII-3)and SSIIIa(SSIII-2)but no polymorphism in other starch synthase related genes were used as test materials.The genotypes of SSIIa and SSIIIa allele were identified by molecular markers,and the allelic effects of SSIIa and SSIIIa gene on amylose content(AC),gel consistency(GC),gelatinization temperature(GT)and rapid visco analyzer(RVA)profile characteristics were analyzed.The significant effects of SSIIa and SSIIIa alleles and the interactive effects between two genes on AC,GT,GC and RVA profile characteristics were found.The SSIIa and SSIIIa alleles from Wujing13 shown positive effects on AC with an average increase of 1.87 and 1.23%in 2 years respectively.There was no significant effect on GT for SSIIa or SSIIIa allele but remarkable influence on GT when the co-existence of the two genes.The genotype SSIIa^(mp)SSIIIa^(mp) shown 1.34℃higher GT than genotype SSIIawjSSIIIawj(mp and wj indicated that the gene was derived from Milky Princess and Wujing 13 respectively,the same as in the below).Different genes and alleles resulted in significant different GC.The genetic effect of SSIIawj and SSIIIamp on GC was 8.74 and 9.62mm respectively.The GC of SSIIa^(wj)SSIIIa^(mp) was 10.64 and 16.95mm higher than that of SSIIa^(mp)SSIIIa^(wj) and SSIIawjSSIIIawj,respectively.The allele SSIIa^(wj) could increase the peak viscosity(PKV),hot paste viscosity(HPV),cool paste viscosity(CPV)and breakdown viscosity(BDV),while decrease the consistency viscosity(CSV)and setback viscosity(SBV).However for the allele SSIIIa^(wj) the opposite was true.The genotype SSIIa^(wj)SSIIIa^(mp) had the largest PKV,HPV and CPV,the genotype SSIIa^(wj)SSIIIa^(wj) had the largest BDV and CSV,but the genotype SSIIa^(wj)SSIIIa^(mp) had the least SBV.According to the comprehensive effect of each trait,the genotype SSIIawjSSIIIamp was the best.The allelic variation and interaction effect of SSIIa and SSIIIa genes have important reference value for improving cooking and eating quality of semi waxy japonica rice.

Classification of archaic rice grains excavated at the Mojiaoshan site within the Liangzhu site complex reveals an Indica and Japonica chloroplast complex

To understand rice types that were utilized during postdomestication and in the modern age and the potential of genetic research in aged rice materials,archaeogenetic analysis was conducted for two populations of archaic rice grains from the Mojiaoshan site during the Liangzhu Period in China(2940 to 2840 BC).Sequencing after the PCR amplification of three regions of the chloroplast genome and one region of the nuclear genome showed recovery rates that were comparable to those in previous studies except for one chloroplast genome region,suggesting that the materials used in this work were appropriate for recovering genetic information related to domestication traits by using advanced technology.Classification after sequencing in these regions proved the existence of Japonica and Indica chloroplasts in archaic grains from the west trench,which were subsequently classified into eight plastid groups(type I–VIII),and indicated that these rice grains derived from different maternal lineages were stored together in storage houses at the Mojiaohsan site.Among these plastid groups,type V exhibited the same sequences as two modern Indica accessions that are utilized in basic studies and rice breeding.It was inferred that part of the chloroplast genome of archaic rice has been preserved in modern genetic resources in these two modern Indica accessions,and the results indicated that rice related to their maternal ancestor was present at the Mojiaoshan site during the Liangzhu Period in China.The usefulness of archaeogenetic analysis can be demonstrated by our research data as well as previous studies,providing encouragement for the possibility that archaeogenetic analysis can be applied to older rice materials that were utilized in the rice-domesticated period.