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。

异亮氨酸调控大鼠小肠黏膜形态和结构的作用机制

作为动物体重要的必需氨基酸,异亮氨酸除了作为蛋白合成底物外,还可促进肠道的吸收功能和屏障功能,但其作用机制尚不清楚.本研究通过体内动物试验和体外细胞试验探究了异亮氨酸对肠道黏膜结构和功能的可能作用机制.试验选用80只远交群大鼠,随机分为4组,饮水添加不同浓度异亮氨酸(0、0.5、2.5和5 mg/mL),试验期为28 d,测定大鼠小肠各段组织结构和空肠中紧密连接蛋白表达水平.体外试验选用大鼠空肠上皮细胞系IEC-6并用不同浓度异亮氨酸处理,通过噻唑兰测定细胞活力,流式细胞术测定细胞的周期和凋亡情况,Western blot分析细胞中紧密连接蛋白表达情况.结果表明,饮水中添加2.5 mg/mL异亮氨酸显著提高了小肠的绒毛高度和绒毛高度隐窝深度比,显著降低了隐窝深度,并显著提高空肠紧密连接表达;适宜浓度异亮氨酸显著促进了IEC-6细胞的增殖并提高细胞中紧密连接蛋白表达量,而高浓度异亮氨酸呈现抑制作用.综上,异亮氨酸可改善小肠的组织结构,尤其促进绒毛生长并提高吸收表面积,其可能作用机制是适宜异亮氨酸可促进小肠上皮细胞的增殖并降低凋亡,进而增大了绒毛的高度;异亮氨酸提高了上皮细胞中紧密连接蛋白的合成,进而促进大鼠空肠的黏膜屏障功能.本研究为异亮氨酸在改善人和动物肠道健康方面的研究和应用提供理论基础.

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.