水稻幼穗培养高效再生系统的建立

本文测试了不同基因型幼穗取材时期、消毒方式、4℃下处理时间、愈伤组织诱导、分化及生根条件等对水稻幼穗培养再生成株的影响,实验结果表明,在优化条件下,籼稻的绿苗分化率在85%以上,成苗率115%左右;粳稻的绿苗分化率在90%以上,成苗率130%左右;粳型广亲和的绿苗分化率、成苗率分别达到85%和115%以上.由此建立了一套高效、可靠、重复性好的水稻组织培养再生系统,为水稻遗传转化的顺利进行奠定了基础.     

水稻幼穗组培及白化苗的电镜观察

木文报道了五份水稻材料的幼穗组培的诱导率和分化率,对继代８次后的幼穗愈伤分化出的白苗和绿苗及其各自的愈伤进行电镜扫描,发现白苗的质体结构不完整,不能正常合成叶绿素。     

野生稻不同外植体的离体培养

野生稻不同外植体离体培养时的幼穗愈伤组织诱导率差异在８．７％￣９４．７％之间,成熟种胚愈伤组织诱导率普遍高于幼穗,但很少能再生绿苗。野生稻幼穗直接分化培养再生绿苗率普遍高于通过愈伤组织培养分化的再生绿苗率。     

不同类型水稻的组织培养和细胞悬浮培养

我们(1980)曾报道过晚粳稻台中育39和杂交水稻汕优6号幼穗、茎、叶鞘等外植体愈伤组织的诱导率、分化率及其试管苗得率的情况及其在温室、大田的性状表现(赵成章等1980),并指出水稻幼穗外植体具有很强的分化能力。因此,本实验以水稻的幼穗为材料,比较研究不同类型水稻品种幼     

提高春小麦花粉植株诱导率的研究

本文研究了影响春小麦花粉植株诱导率的几种主要因素。供试材料为1990年温室种植的杂种F_1代,试验结果表明,诱导培养基中附加细胞分裂素BA或BA与KT相结合能显著提高愈伤组织分化率;0.17M的葡萄糖加0.17M的蔗糖比用0.26M的蔗糖愈伤组织诱导率高60％以上;愈伤组织在18～25℃比在23～25℃下培养绿苗率显著提高;接种前2～3℃预处理幼穗72小时对提高出愈率和绿苗分化率有明显效果。     

不同组织培养途径对小麦再生能力的研究

从现在推广的小麦优良品种和有苗头的新品系中选用10个小麦基因型品种进行组织培养,从愈伤组织诱导率、绿苗分化率等方面比较了幼穗培养、花药培养、幼胚培养三种培养方式的培养效果。结果表明,幼胚培养效果最好,基因型间差异小,都能获得足够数量的再生植株。幼穗的培养效果最差,愈伤组织分化生根和绿芽十分容易,但分化成完整植株则较为困难。花药培养在基因型间差异非常明显而且有较多白化苗。此外,本研究还分析了影响小麦再生能力的因素,建立了一套高效、可靠的小麦组培再生系统,为小麦的转基因技术提供优良的受体材料。     

玻璃温室与田间栽培小麦幼穗分化的比较

以河南省大面积种植的弱春性品种"郑麦9023"及半冬性品种"周麦18"为材料,开展了玻璃温室和田间栽培条件下小麦幼穗分化进程的比较研究。结果表明,在小麦全生育期,玻璃温室内平均温度高于田间环境,小麦幼穗分化所需时间极显著低于田间环境(P < 0.01)。温度和0 ℃以上积温升高,小麦幼穗分化进程加快。与田间种植小麦相比,玻璃温室内小麦幼穗分化缩短的时期主要集中在分化前期(出苗-伸长期、单棱期、二棱期)。玻璃温室内小麦幼穗分化持续时间和总积温均随播期推迟而降低,幼穗分化各阶段出现时间亦随播期的推迟而后延。小麦幼穗分化进程存在品种间差异,其中"郑麦9023"幼穗分化持续时间小于"周麦18",各阶段出现的时间亦早于"周麦18"。温度对幼穗分化各时期的影响存在品种间差异。温度升高对"郑麦9023"幼穗分化中期(二棱期、护颖分化期、小花分化期)影响较大,对"周麦18"幼穗分化前期和后期(单棱期、二棱期、药隔分化期)影响较大。积温对"郑麦9023"护颖分化期和"周麦18"药隔分化期、二棱期影响较大。     

釉稻胚培养力与农艺性状的相关分析

木文研究了32个釉稻品种〔品系）的成熟胚愈伤组织诱导率和绿苗分化率与植株农艺性状的相关 系数,并进行逐步回归分析。结果表明,在釉稻成熟种胚离体培养中,绿苗分化率除与愈伤组织诱导率 有极显著正相关（r二0.758**）外,与生育期、粒长、千粒重、穗长等农艺性状也有显著或极显著相关, 但逐步回归分析表明,绿苗分化率仅与粒长有关,决定系数仅。.21夕。     

一种水稻酰基辅酶A结合蛋白cDNA的鉴定(英文)

对一水稻ｃＤＮＡ 克隆（Ｒ１９０８） 的分析表明, 其可能编码水稻酰基辅酶Ａ 结合蛋白（ａｃｙｌＣｏＡｂｉｎｄｉｎｇ ｐｒｏｔｅｉｎ,ＡＣＢＰ）。Ｓｏｕｔｈｅｒｎ 杂交显示水稻（ Ｏｒｙｚａ ｓａｔｉｖａ Ｌ．） 基因组中仅有一个该基因的拷贝。Ｎｏｒｔｈｅｒｎ 分析表明水稻的ＡＣＢＰ基因在水稻的根、茎、叶、叶鞘、黄化苗和幼穗中皆表达,而以黄化苗的绿苗叶鞘中的表达强度高于绿苗叶片。     

不同时期土壤营养与空气营养对水稻器官生长发育的影响

1.本試驗采用大田竹筒栽培固定土壤因素,改变空間距离的方法,探討水稻在幼穗分化始期前后空气营养对水稻器官生育的影响。采用固定空間距离来控制空气因素,而以大田栽培和竹筒栽培来改变土壤因素的方法,探討水稻在幼穗分化始期前后土壤营养对水稻器官生育的影响。 2.試驗結果初步說明,水稻在幼穗分化始期以前加强土壤营养,而后加强空气营养,对水稻器官的生长发育具有良好的效果。 3.幼穗分化始期加强通风透光处理試驗結果証明:在水稻幼穗分化始期进行放寬行距、缩小株距、稀疏等来加强通风透光处理,以增加生育后期的空气营养,能显著地提高水稻的抗倒伏性,促使稻穗发育良好。 4.从試驗中初步得到的結果,我們认为:水稻群体与外界环境条件的統一过程中,存在着两个基本的矛盾——空气营养和土壤营养,其轉折点可能在幼穗分化始期,在此以前土壤营养是主要的,而后空气营养是主要的,合理調节这两个矛盾(卽空气营养和土壤营养)是密植增产的重要关鍵。     

高温及水稻类型对灰飞虱种群的影响

近年来,灰飞虱Laodelphax striatellus(Fall n)在江浙等地呈明显上升态势。采用不同温度及水稻类型处理灰飞虱若虫,获得灰飞虱种群在不同处理组合下的存活率、发育进度及抗寒力。结果表明,35℃的高温下,灰飞虱各龄若虫无论在杂交籼稻还是粳稻上,其发育进度均比25~30℃推迟2~7d。35℃高温下若虫死亡率较高,并且不能正常羽化。粳稻上饲养的灰飞虱若虫的存活率明显高于杂交籼稻,但水稻类型和温度对灰飞虱存活率的影响不存在明显的互作作用。在适宜温度下(27~30℃)用杂交籼稻饲养的灰飞虱,其过冷却点及结冰点均要比在高温(35℃)或低温(25℃)下饲养的低。在26~30.5℃变温条件下,杂交籼稻上饲养的灰飞虱的过冷却点和结冰点显著低于粳稻上饲养的,而且不同温度和水稻类型上的灰飞虱的过冷却点均低于零下10℃。可见江浙稻区冬季低温对灰飞虱的越冬已不存在制约作用。温度和水稻类型的变化是近年灰飞虱暴发成灾的重要原因。     

Two sequence alterations,a 136 bp InDel and an A/C polymorphic site,in the S5 locus are associated with spikelet fertility of indica-japonica hybrid in rice

The rice indica/japonica hybrid shows strong heterosis.However,such inter-subspecific hybrid can't be directly used in rice production due to its low spikelet fertility.The S5 locus was proved to be associated with fertility of indica/japonica hybrid and its S5n allele from wide-compatibility variety (WCV) is capable to overcome fertility barrier.In the present study,we reported the causal sites in the S5 locus responsible for compatibility of indica/japonica hybrid.Fine-mapping of the S5 locus using the 11...     

High-frequency embryogenesis and plantlet regeneration from isolated microspores of indica rice

We report high-frequency embryogenesis and plantlet development from microspores isolated from anthers of two indica (IR-43, IR-54) and a japonica (T-309) rice cultivars, without prior nutrient preculture of anthers. Pretreatment stress of anthers with mannitol or a sugar-starvation medium, and use of maltose as the carbohydrate source in the microspore culture medium were found to be critical. Co-culture of microspores with rice ovaries was found beneficial but not essential. More than 60% of the microspores of the japonica variety Taipai-309 and 25–45% of the indica cultivars IR-54 and IR-43 showed induction of non-gametophytic development. Consequently, in the best treatments for IR-43 and T-309, more than 500 microspore-derived embryos could be obtained from a single dish (35 mm) containing about 80,000 microspores. Among the indica cultivars, the maximum response was obtained in the basal medium M-019. Plantlet regeneration occurred in about 9% (T-309), 7% (IR-43) and 2% (IR-54) of the transferred embryo-like structures. Received: 6 November 1996 / Revision received: 18 June 1997 / Accepted: 20 August 1997     

水稻原生质体培养及植株再生的研究

由粳稻77-170品系及籼稻品种IR-50的细胞悬浮培养物游离的原生质体,用琼脂糖包埋于RY-2培养基中,发生了持续分裂。前者植板率达2.5％以上,二者最后都再生出植株。对游离和培养方法做了如下改进:1)采用两步法,即先用果胶酶,再用果胶酶和纤维素酶的混合酶进行游离,可避免原生质体发生融合并获得高质量的原生质体;2)悬浮细胞培养基中加入ABA有利于原生质体的存活和分裂;3)琼脂糖包埋培养可大大提高植板率;4)用较高渗透压的培养基培养原生质体再生的细胞团及愈伤组织,可提高植株再生频率。由于这两个品种(系)的培养物都已继代一年半之久,再生植株均为白化苗。这是迄今第一个由籼稻原生质体再生植株的报道。     

Microsatellite diversity within Oryza sativa with emphasis on indica-japonica divergence

The molecular evolution of cultivated rice Oryza sativa L. has long been a subject of rice evolutionists. To investigate genetic diversity within and differentiation between the indica and japonica subspecies, 22 accessions of indica and 35 of japonica rice were examined by five microsatellite loci from each chromosome totalling 60 loci. Mean gene diversity value in the indica rice (H=0.678) was 1.18 times larger than in the japonica rice (H=0.574). Taking the sampling effect into consideration, average allele number in the indica rice was 1.40 times higher than that in the japonica rice (14.6 vs 10.4 per variety). Chromosome-based comparisons revealed that nine chromosomes (1, 2, 3, 4, 5, 8, 9, 10 and 11) harboured higher levels of genetic diversity within the indica rice than the japonica rice. An overall estimate of F(ST) was 0.084-0.158, indicating that the differentiation is moderate and 8.4-15.8% of the total genetic variation resided between the indica and japonica groups. Our chromosome-based comparisons further suggested that the extent of the indica-japonica differentiation varied substantially, ranging from 7.62% in chromosome 3 to 28.72% in chromosome 1. Cluster analyses found that most varieties formed merely two clusters for the indica and japonica varieties, in which two japonica varieties and five indica varieties were included in the counterpart clusters, respectively. The 12 chromosome-based trees further showed that 57 rice varieties cannot be clearly clustered together into either the indica or japonica groups, but displayed relatively different clustering patterns. The results suggest that the process of indica japonica differentiation may have proceeded through an extensive contribution by the alleles of the majority in the rice genome.     

Assessing indica-japonica differentiation of improved rice varieties using microsatellite markers

To assess the indica-japonica differentiation of improved rice varieties, a total of 512 modem varieties including 301 indica and 211 japonica accessions were analyzed using 36 microsatellites. The Fst coefficients ranged from 0.002 to 0.730 among the loci with an average of 0.315. Significant differentiation was detected at 94.4% of the loci studied （P 〈 0.05, pairwise Fst tests）, indicating that there was a high level of indica-japonica differentiation within the improved varieties. At 18 loci, about 74%-98% of the alleles of indica and japonica accessions were distributed in two ranges of amplicon length. Linkage disequilibrium analysis showed that the distribution trends were significantly nonrandomly associated. Using the differentiation trends at the 18 loci, microsatellite index （MI） was proposed for discrimination of the two subspecies. When rice accessions with MI value greater than zero were classified as indica, and those with MI value smaller than zero were classified as japonica, about 96.1% of the accessions could be classified. This result agrees with the classification based on morphological-physiological characters, indicating that this method is feasible and effective.     

In Vitro Culture of Different Explants from Hubei Photoperiod Sensitive Genic Male-Sterile Rice

Young panicles, immature embryos, stem nodes, stem tips, leaf segments, root tips and anthers from Hubei Photoperiod Sensitive Genie Male-Sterile Rice (Oryza sativa subsp, japonica) “Nongken 58” (abbr. 58s) and fertile “Nongken 58” (abbr. 58f) were examined for callus induction, plant regeneration and direct plantlet formation on differentiation medium. 58s and 58f had equal ability in all explants cultures except anther cultures. The induction frequency of the anther callus and the regeneration frequency of the green plant in 58s were much lower than those in 58f, and such differences were not affected markedly by the change of fertility of 58s donor plants. Young panicle, immature embryo, stem node, stem tips showed direct plantlet formation when cultured on differentiation medium containing NAA and kinetin. Different explants produced various types of responses. Young panicles could produce callus and then regenerate plantlets. Evidences from histological observation showed that the plant regeneration in direct plaatlet formation of young panicles were mainly organogenetic, bowever, somatic embryogenesis was also possible.     

PiA水稻悬浮细胞系的建立

本研究以抗稻瘟病的粳稻PiA开花后12～15d的幼胚为材料,将诱导10～15d的愈伤不经固体培养基继代,直接转到AA液体培养基上,在较短时间内成功建立起了优良的水稻悬浮细胞系;并测定了该悬浮细胞系不同时期的生长特性和分化情况,结果表明悬浮培养适宜的继代天数是7～10d;培养30～120d的细胞分化能力和植株再生能力较好,细胞分化率和成苗率分别为57.1%和20%,为进一步利用悬浮细胞进行遗传转化和原生质体分离奠定了基础。     

A procedure for regenerating Japonica and Indica varieties of rice from protoplasts

Fertile rice plants have been regenerated from protoplasts of two japonica rice varieties (Radon and Baldo) using a protocol initially developed for plant regeneration from protoplasts of an indica rice. Embryogenic calli were developed from immature embryos of Radon and Baldo rice on a callus induction medium, and then used to establish cell suspensions. Protoplasts were isolated from the cell suspensions, and cultured on a Millipore filter placed on a Kao/agarose medium that contained cell clusters from suspensions of IR52 or IR45. The protoplasts grew vigorously on Kao medium and developed into embryogenic calli within two to three weeks. Somatic embryo development occurred during a subsequent transfer of the calli to an LS medium for two to three weeks. The calli were then transferred to MS or N6 plant regeneration medium, and within one to three weeks, plants regenerated from 21 to 32% of the Radon calli, and 33 to 35% of the Baldo calli. Based upon these results and the previous success in regenerating an indica variety from protoplasts, this procedure has great promise for regenerating a range of rice varieties, and probably for regeneration of other monocotyledonous plants from protoplasts     

Two sequence alterations,a 136 bp InDel and an A/C polymorphic site,in the S5 locus are associated with spikelet fertility of indica-japonica hybrid in rice

The rice indica/japonica hybrid shows strong heterosis.However,such inter-subspecific hybrid can't be directly used in rice production due to its low spikelet fertility.The S5 locus was proved to be associated with fertility of indica/japonica hybrid and its S5n allele from wide-compatibility variety(WCV)is capable to overcome fertility barrier.In the present study,we reported the causal sites in the S5 locus responsible for compatibility of indica/japonica hybrid.Fine-mapping of the S5 locus using the 11 test-cross families pinpoints a candidate S5 locus encoding aspartic protease(Asp).Intragenic recombination within the Asp gene happened in a number of recombinants,resulting in chimeric S5j-S5n alleles.Just like S5n,the chimeric s5j-S5n allele displayed higher spikelet fertility when combined with the S5i allele.In the complementary test,however,the S5n allele from WCVs failed to enhance fertilities of the indica/japonica hybrids.Compared to both indica and japonica varieties.all nine WCVs from different resources are characterized with a 136 bp deletion in the Asp N-terminus.which probably renders the S5n allele non-functional.Furthermore,an A/C polymorphic site is detected 1,233 bp downstream of the Asp start codon.The heterozygous A/C site of the Asp gene in indica/japonica hybrid is believed to be the casual factorto causc partial sterility.The functional makers based on the two polymorphic sites will be broadly used in developing wide-compatibility rice varieties.