高直链淀粉含量杂交水稻新组合川香优37的选育及栽培技术要点

川香优37系四川省农业科学院水稻高粱研究所应用四川省农业科学院作物所育成的三系不育系川香29A与自育恢复系泸恢37组配育成的中籼迟熟杂交稻新组合,2013年通过四川省农作物品种审定委员会审定。该组合具有直链淀粉含量高,丰产性突出,稳产性好,适应性广,抗稻瘟病能力较强等特点,适宜在四川省平坝丘陵区种植。     

双波长比色法测定糜子中直链/支链淀粉含量

为建立一种同时测定糜子中直链和支链淀粉含量的简便方法,充实糜子理化性质的相关研究,首先应用双波长比色法,结合糜子直链淀粉/支链淀粉—碘复合物的吸收光谱图,确定其测定波长与参比波长。并利用标准工作曲线,求出样品中直链/支链淀粉的含量。由全波长扫描图谱确定了糜子中直链淀粉测定波长与参比波长分别为613 nm与520 nm,支链淀粉的测定波长和参比波长分别为538 nm与700 nm。结果表明,直链淀粉与支链淀粉的浓度分别在0~0.15 mg/mL和0~0.125 mg/mL呈线性相关。实验室用此法对15份糜子种质中直链与支链淀粉的含量进行测定。通过精密度与回收率实验,测得直链与支链淀粉的6次的标准偏差分别为0.145与0.022,回收率范围85.3%~97.9%。试验结果均满足分析要求,所建立的方法具有简便、快速、准确等特点,可用于测定糜子中直链和支链淀粉的含量。可对糜子口感及品质进行评价,从而筛选出优良种质。     

Evaluation of the waxy endosperm trait in proso millet (Panicum miliaceum)*

The entire USDA‐ARS maintained collection of 650 accessions of proso millet (Panicum miliaceum L.) was evaluated for the presence of accessions with waxy (amylose‐free) endosperm starch. Six accessions, five of which derived from mainland China, were identified. Segregation ratios for waxy endosperm were evaluated in F₂ and F₃ populations derived from crosses between two waxy accessions, PI 436625 (Lung Shu 16) and PI 436626 (Lung Shu 18), and several wild‐type accessions. The waxy trait was found to be under the control of duplicate recessive alleles at two loci, herein designated wx‐1 and wx‐2. Wild‐type alleles at these loci were designated Wx‐1 and Wx‐2. Iodine‐binding revealed a mean grain‐starch amylose concentration of 3.5% in waxy lines and 25.3% in wild‐type proso. Expression of the granule‐bound starch synthase (waxy protein) in waxy lines was reduced to approximately one‐tenth that of wild‐type accessions. The waxy accessions identified now are available for the introgression of this trait into breeding lines adapted to the Great Plains of North America.     

Influence of single-nucleotide polymorphisms in the gene encoding granule-bound starch synthase I on amylose content in Vietnamese rice cultivars

Amylose content is one of the most important factors influencing the physical and chemical properties of starch in rice. Analysis of 352 Vietnamese rice cultivars revealed a wide range of variation in apparent amylose content and the expression level of granule-bound starch synthase. On the basis of single-nucleotide polymorphisms (SNP) at the splicing donor site of the first intron and in the coding region of the granule-bound starch synthase I gene, Waxy gene, alleles can be classified into seven groups that reflect differences in apparent amylose content. The very low and low apparent amylose content levels were tightly associated with a G to T in the first intron whereas intermediate and high amylose was associated with a T genotype at SNP in exon 10. The correlation between the combination of T genotype at SNP in the first intron, C in exon 6, or C in exon 10 was predominant among low amylose rice varieties. Our analysis confirmed the existence of Wx^op allele in Vietnamese rice germplasm. The results of this study suggest that the low amylose properties of Vietnamese local rice germplasm are attributable to spontaneous mutations at exons, and not at the splicing donor site.     

香蕉果实抗性淀粉含量变化及其与其他类型淀粉相关性分析

【目的】研究香蕉果实抗性淀粉形成机理,为选育高抗性淀粉香蕉品种和调控抗性淀粉合成提供理论基础。【方法】以 ‘巴西’蕉（Musa acuminata L. AAA group cv. Brazilian）果肉为试材,对香蕉果实采前和采后抗性淀粉含量变化及其与其他类型淀粉相关关系进行分析。【结果】香蕉果实发育过程中,总淀粉、直链淀粉、支链淀粉及抗性淀粉含量整体呈上升趋势,后熟过程中各种淀粉含量逐渐下降;乙烯处理加速了总淀粉、直链淀粉和支链淀粉的降解,但抗性淀粉降解速度较自然后熟慢;1-MCP处理香蕉果实各种淀粉含量呈先增后降的单峰曲线变化。相关性分析表明：香蕉采前果实抗性淀粉合成与直链淀粉含量变化呈显著正相关,与总淀粉和支链淀粉含量变化不相关;1-MCP处理后,抗性淀粉含量变化与直链淀粉含量达到显著正相关水平,与总淀粉含量变化不相关。【结论】香蕉果实抗性淀粉形成与直链淀粉含量密切相关,在香蕉果实发育过程中可通过调控直链淀粉含量促进抗性淀粉合成。     

近红外反射技术建立合肥地区精米直链淀粉含量测定模型

以合肥地区种植的203份水稻材料为检测对象,用近红外反射技术采集光谱,常规化学方法测定精米直链淀粉含量。结果表明,定标样品的直链淀粉含量分布范围为3.439%～28.046%,代表性和连续性良好。采用多种计量数学处理方法和偏最小二乘法(PLS),优化建立了精米直链淀粉含量的定量分析预测模型。定标集(C-Set)样品数132个,相关系数(Rc)0.9278,定标标准差(SEC)1.6582;验证集(V-Set)样品数67个,相关系数(Rv)0.8736,预测标准差(SEP)1.9083,并证实所建立的模型在测定精米直链淀粉含量上具有很好的准确性和实用性,对合肥地区水稻品质育种及种质资源相关研究具有实用价值。     

施氮时期对寒地不同品种水稻产量和品质的影响

施氮时期对不同处理两个品种水稻产量影响差异很大,方差分析FV7=38.27**;FV10=19.01**;都达到了极显著水平。大穗型水稻V7的处理1(基肥)产量最高,分别比其它处理(3,2,4)增产9.64%,12.22%,14.96%。穗数型水稻V10的处理2(基肥+蘖肥)产量最高,分别比其它处理(3,4,1)增产6.35%,13.03%,19.08%。施氮时期对水稻蛋白质的含量影响明显,两个品种水稻均以处理3(基肥+穗肥)蛋白质含量最高,其次是施粒肥。随着施氮时期的后移,水稻直链淀粉的含量有下降趋势。     

酶法链淀粉流变特性的研究

用异淀粉酶对淀粉进行切枝，研究了酶变性后淀粉糊的流变特性及其影响因素。结果表明：在ω（淀粉糊）为2%-6%，湿度25-70℃的实验条件下，酶解链淀粉呈现假塑性流体特征，具有触变性和剪切稀化性质，淀粉糊的链淀粉含量，浓度，温度等因素对其表观粘度有较大的影响。     

水稻直链淀粉含量的分子遗传研究

为选育高产、优质、直链淀粉含量中等的杂交稻组合，用23个非糯水稻纯系品种（系）及其所配22个组合的F1代，研究了微卫星标记484／485的PCR扩增产物（CT）n多态性，484／W2R的PCR扩增产物被AccⅠ酶切多态性，二者与直链淀粉含量的相关性，亲本与F1直链淀粉含量的相关性，结果表明，供试纯系材料有3种多态片段，即（CT）11，（CT）18和（CT）20，其中（CT）11或（CT）18的品种数多；484／W2R扩增产物能或不能被AccⅠ酶切的品种数比较接近；484／485扩增产物（CT）n多态性和484／W2R扩增产物被ACCⅠ酶切的多态性与直链淀粉含量极显著相关；杂种F1直链淀粉含量与双亲平均值极显著正相关，直链淀粉含量偏高的籼稻品种与直链淀粉含量偏低的粳稻品种杂交，杂种F1直链淀粉含量中等的组合数多。