Advances in Breeding of High-amylose Indica Hybrid Rice Combinations in Sichuan Province

During 2000-2013, totally ten high-amylose specific hybrid rice combinations approved and five combinations for production test were bred in Sichuan Province. In the paper, rice yield, economic traits, quality indicators and rice blast-resistance identification results of these 15 hybrid combinations were described and analyzed. Results show that Chuanxiangyou37 and Tianlongyou540 have relatively high amylose content, good yielding ability, high resistance and appropriate growth period, which are new hybrid rice varieties with organic combination of high amylase content, high gel consistency, high yield, stable yield and wide adaptability. Therefore, Chuanxiangyou37 and Tianlongyou540 are recommended as the main combination for rice production.

Relationship Between the First Base of the Donor Splice Site of Waxy Gene Intron 1 and Amylose Content in Yunnan Indigenous Rice Varieties

There exists a single nucleotide polymorphism, G or T, at the first base of the donor splice site of waxy gene intron 1 in rice. In order to study the relationship between the first base of the donor splice site of waxy gene intron 1 and amylose content in rice, the one-step PCR method was used to determine whether it is G or T in 220 Yunnan indigenous rice varieties from 14 districts, 55 towns/counties of Yunnan Province, and 101 varieties of which were validated by the PCR-Acc I method. According to the G/T polymorphism, 164 rice varieties showed GG-genotype, while the other 56 fell into TT- genotype, accounting for 74.5% and 25.5% of all the test varieties, respectively. When all the rice varieties were divided into indica and japonica subspecies, it was found that 80.5% of indica rice and 67.0% of japonica rice belonged to GG-genotype. The rice varieties with GG-genotype had significantly higher amylose content （18.95% on average） than those with TT- genotype （all below 16%）, but 33 rice varieties with GG-genotype still had low amylose content ranging from 3.91% to 15.93%, and most of them came from the Dai minority area in the Southwest of Yunnan Province. However, there was no significant difference in the mean amylose content of the same GG or TT genotypes between indica and japonica rice, suggesting that different genetic backgrounds, indica or japonica, had no effect on amylose content. The coefficient of correlation between the genotype and amylose content was 0.733 （P〈0.01）.

Amylose Content and Starch Granule Size in Rice Grains are Affected By Growing Season

Amylose content and starch granule size in grains influence rice quality,which differs between the early(ES)and late season(LS).The objective of this study was to determine the variation of amylose content and starch granule size between seasons and find the main reasons(e.g.,temperature and solar radiation)for the observed variation.Field experiments with six rice varieties(three high and three low amylose content rice)planted in the ES and LS were conducted in 2016 and 2017,respectively.The mean temperatures during the filling stage were higher in ES,however,the daily temperatures at 7-10 days after flowering(DAF)in 2016,and at 5-10,13-14 DAF in 2017 were higher in LS.The results showed that amylose content in LS was lower than in ES with high amylose content rice varieties(HACV);the opposite trend occurred with low amylose content rice varieties(LACV).The mean starch granule diameter was higher in LS than ES in 2016,but the opposite result occurred in 2017 with all rice.Our results suggest that higher temperatures increased and decreased the amylose content in HACV and LACV,respectively.Temperatures at 5-15 DAF were important for the formation of starch granules:lower temperatures during 10-14 DAF increased the proportion of larger starch granules(d>6.21μm,some with d>13.3μm),and higher temperatures at 5-6 DAF increased the proportion of starch granules with diameter 4.24-6.21μm.

The Current Breeding Situation and Development Strategies on High-quality Inbred Rice in Guangxi

According to the rice quality,production and resistance of 50 high-quality inbred rice varieties bred and examined and approved in Guangxi during the period 2000-2011,we analyze the current breeding situation and existing problems concerning high-quality inbred rice va- riety in Guangxi: the rice quality has been greatly improved,but the amylose content is still low; a series of scented rice varieties with high quality and high yield have been bred,such as Zhongguangxiang No. 1,Sanxiang 628,Guixiang No. 1,Liufengxiangzhan,Jiafuxiang No. 1, Zhaoxiang No. 1; the production of high-quality inbred rice during the period 2009-2011 was significantly enhanced,annually more than 66 00 kg / ha,but the disease resistance of rice variety bred was generally poor,and disease-resistant breeding stuck in the mud. Henceforth it is necessary to be oriented by the rice market,and take the rice type with long grain,high adhesive strength,medium-low amylose content and low chalkiness degree as the breeding objectives; introduce the existing high-quality variety resources with medium amylose content at home and abroad,then directly use them or innovate upon them as hybrid strain; take the thick-and-long-grain rice type as breeding objectives,and further improve the yield per unit area of high-quality inbred rice by improving the thousand-grain weight; increase capital investment,improve breeding techniques,strengthen disease-resistant and degeneration-resistant breeding,and improve the application of modern biotechnology in the breeding of high-quality inbred rice.

种植季节对高直链淀粉水稻品种淀粉消化特性的影响

为探究早季与晚季不同种植季节对高直链淀粉水稻消化特性的影响,本研究以6个高直链淀粉水稻为供试品种,于2020-2021年进行早、晚季种植,通过体外消化模拟方法结合气象数据,研究高直链淀粉水稻在早季种植时和晚季种植时的淀粉消化特性的差异。结果表明,高直链淀粉水稻在早季种植时,灌浆期平均温度和平均辐射量比晚季种植分别高16.1%和10.1%。总葡萄糖生成量(total glucose production, TGP)和葡萄糖生成速率(glucose production rate, GPR)比晚季种植时分别降低4.1%和10.0%,而活跃消化时间(active digestion duration, ADD)增加7.8%。与晚季种植相比,高直链淀粉水稻在早季种植时直链淀粉增加3.1%,蛋白质降低8.5%。稻米RVA谱特征值中峰值黏度、最低黏度、崩解值、最终黏度、回复值和糊化温度分别增加34.4%、29.7%、51.6%、26.2%、20.6%和1.3%,而消减值降低2.6%。相关性分析表明,GPR与直链淀粉含量、峰值黏度、最低黏度和最终黏度呈显著负相关关系,相关系数分别为–0.429、–0.558、–0.662和–0.439,与蛋白质含量呈显著正相关关系,相关系数为0.565。直链淀粉含量、峰值黏度、最低黏度都与灌浆期的日平均温度和日平均太阳辐射呈显著正相关关系,蛋白质与灌浆期的日平均温度和日平均太阳辐射呈显著正相关关系。由此可知,高直链淀粉水稻品种在早季种植后,灌浆期日平均温度及日平均太阳辐射量增加,导致直链淀粉含量、峰值黏度、最低黏度和最终黏度增加,蛋白质含量降低,进而导致淀粉消化速率变慢。本研究结果可为高直链淀粉水稻品种淀粉消化快慢的栽培调控提供理论依据。

广西优质常规稻育种现状及发展对策

根据2000～2011年广西育成并通过审定的50个优质常规稻品种的米质、产量、抗性等,分析了广西优质常规稻品种育种现状及存在问题,如米质虽已取得较大改良但直链淀粉含量仍偏低;育成了一系列米质优且产量高的香稻品种如广香1号、三香628、桂香3号、柳丰香占、家福香1号、兆香1号等;近3年(2009～2011年)的优质常规稻产量明显稳定提升,每年均超过6600kg/ha,但育成水稻品种抗病性普遍较差,抗病育种徘徊不前等。今后需根据稻米市场导向,以长粒型、高胶稠度、中等偏低直链淀粉含量、低垩白度的大米类型为选育目标;引进国内外现有的中等直链淀粉含量的优质品种资源,直接或创新后作为杂交亲本加以利用;以粗长粒型作为选育目标,通过提高千粒重来进一步提高优质常规稻的单产;加大资金投入,提高育种技术,并加大抗病及抗逆育种力度,提高现代生物技术在优质常规稻育种中的应用等。

浙江与日本粳稻直链淀粉含量的比较

对浙江省 1994— 1998年育成的 96份粳稻材料的分析表明 ,浙江省粳稻品种的稻米直链淀粉含量变化幅度较大 ,较低的与日本优质粳稻“越光”相似 ,高的超过“越光”的两倍以上。进一步研究表明 ,浙江省最近育成的粳稻新品系的稻米直链淀粉含量仍偏高 ,若通过严格的筛选 ,有望选育出稻米直链淀粉含量适宜的粳稻新品种。与之相反 ,日本粳稻品种的稻米直链淀粉含量一般在13%～ 18%之间 ,各品种间差异较小。水稻品种的稻米直链淀粉含量随环境条件的变化而变化 ,同一品种在杭州栽培的稻米直链淀粉含量要比在日本福井栽培的平均高 1.6 %。一般年度间稻米直链淀粉含量差异为 2 %左右。早熟品种的稻米直链淀粉含量较高 ,随环境条件的变化较大。

镉低积累水稻品种筛选及其在镉超标稻田的表现评价

【目的】筛选镉低积累型水稻品种并开展镉超标稻田表现评价研究,为广西中低度镉污染稻田生产安全稻米提供品种和数据参考。【方法】以114份(V1~V114)水稻低镉品种育种材料为试验对象,从中筛选综合性状优良且籽粒表现为镉低积累的目标材料;对目标材料进行大田试验和盆栽试验验证,测定其在广西不同试验点的农艺性状和精米镉含量。【结果】初步筛选试验的114份参试材料中,除V102的精米镉含量低于最低检测值外,其余113份水稻育种材料的精米镉含量范围在0.01~0.35 mg/kg,平均值为0.10 mg/kg,筛选得到综合性状优良且精米镉含量较低的材料V111(审定后名称为桂育12)。桂育12在中低度镉污染区大田验证种植时,精米镉含量(0.01~0.10 mg/kg)未超出国家标准GB 2762—2017《食品安全国家标准食品中污染物限量》规定的限值(0.20 mg/kg)。盆栽试验结果表明,在pH为5.0,土壤镉含量3.0 mg/kg条件下,桂育12精米镉含量(0.34 mg/kg)有超标风险;各试验中土壤镉含量对桂育12部分农艺性状指标影响显著(P<0.05),但属于品种种植的正常波动范围,对米质和产量的综合影响有限。【结论】从114份水稻材料中筛选出的镉低积累品种桂育12,经多年多点试验验证,在中低度镉污染稻田产出的稻米镉含量不超标,籽粒镉低积累性状较稳定,综合性状表现受土壤镉含量影响较小,可在广西中低度镉污染稻田推广应用。

利用Wx基因微卫星标记快速育成中等直链淀粉含量的籼型优质不育系

本研究利用Wx基因微卫星特异性分子标记"484/485"对13份国内常用保持系进行PCR检测,筛选出具有中等AC含量、Ⅰ型带型的优质保持系"宜香1B"作为优质供体。配制"协青早B/宜香1B",对其F1、F2代单株用"484/485"PCR分子检测,证明其带型符合一对基因分离模式。在此基础上,对"协青早B/宜香1B"的杂交、回交和自交的低世代群体(BC1F1、BC1F2)进行"484/485"分子标记辅助选择,再结合优质不育系其它性状选择,快速育成了中等AC含量、垩白率低、透明度高、不育特性和农艺性状稳定的籼型优质三系不育系"浙农3A",并于2009年9月顺利通过了浙江省品种审定委员会组织的专家现场鉴定。本文还就利用"484/485"分子标记有效改良稻米AC含量等问题进行了讨论。

稻米直链淀粉含量与结实期温度间的关系研究

１９８８年用不同类型的１９个水稻品种在全国１３个试点的分期播种试验和１９８９年的人工气候箱控温试验结果表明：结实期日均温是影响直链淀粉含量（Ａｍｙｌｏｓｅｃｏｎｔｅｎｔ，ＡＣ）的最显著温度因子；大部分品种的ＡＣ与结实期温度间存在二次曲线关系，高ＡＣ品种在较高温度下的ＡＣ最大，而中、低ＡＣ品种的ＡＣ在较低温度下达到品种的最大ＡＣ值，ＡＣ对温度的敏感性同温度的高低有关，并存在品种类型间的差异；ＡＣ主要受结实前期的温度控制。

油稻稻三熟制早熟高产油菜品种筛选

为筛选适合江西省油稻稻三熟制种植的早熟高产优质油菜品种,引进阳光131、川油1号等15个双低油菜新品种,对其早熟性、抗性、产量和日均产量等进行了比较。结果表明:从早熟性来看,川油1号、川油3号、阳光131及沣油320熟期较早,赣两优5号和赣油杂9号熟期偏晚;从抗性来看,阳光131、中油杂24、圣光127、黔油早2号、丰油730、沣油847及赣油杂8号7个品种抗性能力较强;从产量和日均产量来看,阳光131、中油杂24、庆油1号、圣光127、黔油早2号、浔油9号、丰油730、沣油847、沣油320和赣油杂8号10个品种较高;通过对15个油菜新品种综合性状的考察,阳光131、中油杂24、圣光127、黔油早2号、丰油730、沣油847及赣油杂8号等品种抗倒性和抗菌核病强,产量及日均产量高,熟期适宜,适合在江西省作为油稻稻三熟栽油菜品种推广种植。

乳熟阶段短期高温对不同品种早籼稻直链淀粉含量和RVA谱特征参数的影响

以2个杂交稻(淦鑫203和金优402)和4个常规稻(中531、B670、E134和ST66)为材料,于水稻乳熟期进行高温处理3d,处理温度分别为35℃和38℃,以同期田间自然温度为对照,研究乳熟期高温对不同品种早籼稻直链淀粉含量和RVA谱特征参数的影响,并对稻米淀粉RVA谱特征值与直链淀粉含量进行相关分析。结果表明,无论是对照还是高温处理,中531和B670的直链淀粉含量、消减值及回复值较低,但崩解值较高,而E134和ST66表现为直链淀粉含量、消减值及回复值较高,崩解值较低;杂交稻淦鑫203和金优402则介于两者中间。与对照相比,38℃高温显著降低淦鑫203、金优402、中531和E134的崩解值,显著提高淦鑫203、中531的消减值、显著降低金优402、中531、B670和E134的回复值。各处理淀粉RVA谱变化趋势较一致,但因品种及温度而略有差异。38℃高温处理下稻米淀粉黏滞性曲线始终低于对照,但常规稻中531和B670的RVA谱形态与对照差异不大。此外,稻米直链淀粉含量与RVA谱各特征值间存在显著相关性。

高直链淀粉含量早籼组合优Ⅰ315的选育与应用

优Ⅰ315是用高异交率优质不育系优ⅠA为母本,与自选恢复系测315配组而成的杂交水稻早籼组合。该组合具有产量高、直链淀粉含量高(26.8%)、制种产量高等特点,可作为米粉加工型专用稻利用。该组合于2003年2月通过广西壮族自治区农作物品种审定委员会审定。文章介绍了其选育经过、特征特性及其应用技术。

加工专用型杂交中籼新组合绵2优151的选育与应用

绵 2优 15 1是用具高直链淀粉含量的新不育系绵 2A与高配合力恢复系江恢 15 1配组而成的杂交中籼新组合 ,具有产量高、直链淀粉含量高 (2 6.5 % )、制种产量高等特点 ,可作为米粉加工型专用稻利用 ,于 2 0 0 2年 3月通过四川省农作物品种审定委员会审定。介绍了其选育经过、特征特性及其应用技术。

吉林省西部地区苏打盐碱地水稻新品种筛选试验

在吉林省西部镇赉县进行了14个水稻品种的比较试验研究,通过对相关熟期、产量、稻米米质和农艺性状进行综合分析,筛选出了5个比较适合当地气候的水稻品种,分别是吉粳113、吉粳301、吉粳303、吉粳88和吉粳515,为筛选适宜当地种植的水稻新品种提供理论基础。

中日水稻品种的食味比较

近年来日本稻米品质和食味研究取得了举世瞩目的成就。在中国,由于经济快速发展,稻米食味研究逐渐展开,为了给中国优质食味品种选育提供理论依据,从1998年开始对中日品种进行食味比较研究,以食味理化特性及品尝鉴定试验研究结果为依据,分析了中国水稻品种食味特性,即低直链淀粉含量和低蛋白质含量兼备的品种很少,结果导致食味品尝试验各项目的平衡性不好,综合评价不如日本优良食味品种。

水稻低直链淀粉资源筛选

为了在水稻外观品质改良的同时提高食味品质,通过对引自IRRI及中国水稻种质资源库的1000多份材料测定直链淀粉含量,并对IRRI资源测定外观品质。研究发现:目前水稻优良食味品种多数外观品质差,且“软米”标准欠缺。水稻直链淀粉含量分布十分宽,其中软米范围品种数量少,糯米品种较软米品种多,且分为优质糯稻与劣质糯稻两类。其他类型品种数量最多,直链淀粉含量变异最大,软米类型品种蛋白质含量显著高于糯稻及较高直链淀粉含量品种。本试验通过筛选获得12份软米资源,为软米选育提供了多样化资源,并给出了一个软米判定标准。

云南地方稻种Wx基因第一内含子供体+1位碱基变异与直链淀粉含量的关系

应用PCR一步法对来自云南省14个地州、55个市／县的220个籼、梗地方稻种Wx基因第一内含子供体＋1位碱基G／T进行了检测，同时用PCR—AccI酶切法对其中的101份进行验证，结果表明两种方法检测结果一致。根据G／T碱基将220个供试材料分为GG、TT两种基因型。云南地方稻种以GG型占优势，有164个，占74．5％;TT型有56个，占25．5％；籼稻中80．5％属GG型，粳稻中67．0％属GG型。GG型直链淀粉含量较高，平均18．97％，TT型较低，均低于16％，GG、TT基因型之间的平均直链淀粉含量差异极显著。G／T与直链淀粉含量存在密切的联系，其相关系数为0．733＊＊。GG型品种中有33个直链淀粉含量较低（3．91％～15．93％），多数为来源于云南西南部傣族地区的品种。籼稻中的GG型或TT型品种与粳稻中的GG型或TT型品种间平均直链淀粉含量无显著差异，表明GG／TT基因型在籼粳不同遗传背景下直链淀粉表达无显著差异。

高直链淀粉水稻的淀粉积累及相关酶活性关系研究

研究高直链淀粉型水稻品种菲优188花后各时间段内籽粒中不同类型淀粉含量和积累速度的变化,以及淀粉合成相关酶活性的变化,结果发现:该品种花后不同时间段内直链淀粉、支链淀粉、总淀粉含量及其相关酶活性均存在极显著差异。直链淀粉和支链淀粉的积累规律相似,均呈Logistic曲线方程式积累,直链淀粉和支链淀粉积累速度随时间的变化规律也相似,且均与淀粉合成酶呈极显著正相关性。

高通量快速检测稻米中表观直链淀粉含量的方法

为了便于高通量筛选直链淀粉含量变化的诱变突变体,对农业部标准中的直链淀粉含量测定的方法(NY/T 83—1988)进行了改良。改良法测定结果与标准法高度正相关。与标准法相比,改良法具有简单、易操作、样品量少等优点,特别是如果表观直链淀粉含量差异超过5%左右,I2-KI染色的差异就能用肉眼很直观的区分,因此该方法可用于微量样品的直链淀粉含量测定或高通量育种群体的筛选测定。