杂交水稻种子裂颖研究

杂稻种子存在着严重的裂颖现象。本研究表明,经过脱粒和干燥的汕优63种子的实粒裂颖率为16.3%。在贮藏过程中,裂颖粒种子的生活力迅速衰退,严重影响混合种子群体的发芽及幼苗生长。裂颖是不育系的一种遗传特性,某些制种措施不恰当的脱粒和干燥也会加剧裂颖。选育闭颖能力强的不育系、改进制种技术等可防止或减少裂颖。生产上通过选种尽量剔除裂颖粒,采用湿润浸种、旱育秧等措施可减经裂颖粒的危害。     

杂交水稻种子裂颖研究

1 裂颖的危害水稻谷粒的内颖与外颖的两缘相互勾合包被着糙米,构成完全封闭的谷壳。但杂交稻种子及其不育系却有严重的裂颖(包括谷壳裂纹和开裂)现象。种子裂颖在成熟期易导致穗上发芽;在种子贮藏过程中,裂颖粒(特别是其中的开裂粒)种子的生活力迅速衰退;催芽和育秧时,胚乳物质易外渗,严重影响整个种子批的发芽及幼苗生长,使混合种子(正常粒与裂颖粒自然混合)的发芽势、发芽率、成     

水稻三系不育系繁殖倒伏发生原因及防治措施研究

从水稻三系不育系倒伏现象、类型及危害着手,分析了不育系繁殖倒伏发生的原因,不育系倒伏主要受三大因素的共同制约,即气候因素、栽培因素及亲本内在遗传因素.提出了合理密植,保证基本苗;科学管水,平衡施肥;科学喷施"920"等有效防治水稻倒伏的技术措施.     

水稻种子裂颖对发芽率的影响

杂交水稻种子中除常见的秕粒、空壳、病粒、机械或害虫损伤粒及杂质外，稻种的内、外颖开裂是另一类常见现象。笔者随机抽取１９９８年生产的杂交稻种５个样品进行调查发现，颖壳开裂粒占总调查粒数的２１．６％～６２．２％，其中开裂程度重的在１４．７％～３７．３％，...     

杂交稻及其三系种子混杂的原因及其防止措施

杂交稻种子的纯度高低,直接关系到大田杂种优势的利用,大量调查表明：杂交稻种子纯度每降低山,每公顷将减产60～75公斤,严重的达150公斤左右。因而新颁布实施的《农作物种子质量分级标准》以品种纯度作为划分种子质量级别的主要依据。杂交稻种子是由不育系和恢复系配制而成,不育系的繁殖又要由保持系授粉而产生。因此在“三系”繁殖和杂交稻制种中的任何一个环节发生问题,都会影响到杂交稻种子的质量。本文分析了杂交稻及其“三系”种子混杂原因,并提出防止混杂的措施。1“三系”中主要杂株类型及其产生的原因1．1不育系中杂株主要是…     

杂交水稻正常种子与裂颖种子发芽试验方法研究

通过对杂交水稻的正常种子及裂颖种子设置不同的发芽床、不同的浸泡处理进行发芽试验,分析比较它们之间的差异,探索最佳的浸种、催芽方法。结果表明,砂床促进种子发芽,强氯浸泡对裂颖种子发芽有抑制作用。     

提高不育系种子质量的管理措施

提高不育系种子质量的管理措施,采用低代株系繁种,严格花期隔离,严格田间去杂去劣,适时收获防穗发芽,严防收、晒、贮机械混杂和霉变。     

提倡有裂颖性的水稻品种旱育秧

裂颖是导致杂交稻种子发芽率降低的主要原因之一,为了充分发挥出部分具有裂颖特性的优质杂交稻品种的高产、优质的潜能,抓好育秧环节是关键所在.通过旱育秧,可以适当提高具有裂颖特性的杂交种子的发芽率,从而确保全苗、高产.     

裂颖与去壳对水稻种子萌发生理的初步研究

利用3个在四川生产应用比较普遍的杂交水稻品种为材料,将试验种子做裂颖、去壳处理,以正常颖壳种子为对照,研究颖壳对种子萌芽生长的影响.结果表明,萌芽速度、物质运转效率和贮藏物质消耗率为:去壳＞裂颖＞完整;随萌发时间的延长,α-淀粉酶活性下降速率为:去壳＞裂颖＞完整;根冠比为:去壳＜裂颖＜完整;叶绿素含量为:完整处理为最高,裂颖与去壳偏低.表明颖壳对水稻种子正常萌芽至关重要,是水稻幼苗健康生长的保障,是培育优质稻苗的基础.     

早籼三系不育系29A的特征特性及应用

29A系江苏沿海地区农科所以珍汕97B与V20B杂交再与珍汕97A回交转育而成的籼型三系野败型不育系,2003年1月通过江苏省农作物品种审定,是江苏省育成的第一个籼型三系不育系.用29A与盐恢559配组育成的新组合29优559综合性状突出,亦于2003年1月通过江苏省农作物品种审定.     

东北新三系杂交粳稻BT型不育系开花习性的研究

以东北最新育成的三系粳稻不育系和保持系为材料,研究了不育系和保持系的开花习性.结果表明,8个不育系的开花习性可以分为2类,A1、A2和A3可以分为一组,即始花时间早,终花时间也较早,花期集中,开花持续时间只有3h.其他5个不育系分为另一组,始花时间较晚,终花时间也晚,开花时间长,开花高峰晚,基本都集中在12∶30～13∶00时,午前花率很低,平均在20.6%,最高为24%.不育系的异交结实率和柱头外露率、开颖时间成极显著的正相关,相关系数为0.974.和0.839.     

发展杂交棉三系不育系的必要性和可能性

<正>我国杂交棉种植面积逐年扩大,长江流域棉区基本全部种植杂交棉,黄河流域棉区杂交棉种植面积达30%左右,新疆棉区也在积极推广杂交棉种植。但目前杂交棉种的生产成本逐年上升,销售价格逐年下降,种子生产、销售各环节的利润越来越少,发展三系不育系制种是解决目前困境的有效方法。     

Assessment of purity of rice CMS lines using cpDNA marker

AFLP technique was used to analyse the polymorphism between rice cytoplasmic male sterility (CMS) line Jin2A and its maintainer Jin2B. A stable differential band was discovered, and sequence analysis showed that Jin2A contained a more tandem repeat of 6 base pairs (AGAAAA) than Jin2B. Further studies confirmed that the diversity came from cpDNA and occurred at three kinds of abortive cytoplasmic genotypes. Accordingly, specific primers were designed and utilized to assess the purity of rice CMS lines during multiplication with pollen fertility and seed setting rates of bagged panicles as control. The result indicated that this cpDNA locus could be utilized to precisely distinguish maintainer plants from rice CMS lines. PCR analysis was consistent with that from Grow-out test in CMS line seed purity assessment during multiplication, despite it was helpless in distinguishing F₁ hybrids from CMS lines due to similar cytoplasms. Because of fewer hybrid and more maintainer off-plants, this cpDNA locus was still appropriate for seed purity assessment of rice CMS line during multiplication. This is first report that a marker on cpDNA could be utilized to assess the genetic purity of rice CMS lines with three abortive cytoplasmic genotypes.     

黑龙江省化肥污染防控对策研究

农业面源污染是当前农业生态环境保护的一大难题,化肥作为农业面源污染的主要来源,能否得到有效控制是农业面源污染能否得到有效治理的关键。黑龙江省存在化肥施用强度过高,氮、磷、钾肥施用比例失衡等严重问题,分析了化肥污染现状、产生的原因,从提高环保意识、增加财政投入、调整施肥结构等方面提出治理对策。     

植物“黄叶病”的成因及其防治

由于生态环境的不断恶化,植物“黄叶病”的发生日益普遍和严重。引起植物“黄叶病”的因素可分为生物性和非生物性因素两种,不同类型的“黄叶病”在发病症状,发生规律,防治方法上也存在着一定差异。本文对植物“黄叶病”的发生原因、诊断方法和防治措施等方面的研究成果进行了综述,并对以后的防治和应密切关注的问题进行了探讨,以期为植物“黄叶病”的研究和防治提供参考和借鉴。     

Identification of stable maintainer and fertility restorer lines for 'Polima' CMS in Brassica campestris

‘Polima’ cytoplasmic male sterility (CMS) was transferred from ‘Polima’ Brassica napus ‘ISN 706’to five different cultivars of Brassica campestris (‘Pusa kalyani’, ‘Pant toria’, ‘Candle’, ‘Tobin’ and ‘ATC 94211′) by repeated backcrossing. It was observed that, while ‘Polima’ CMS manifested complete and stable male sterility in the nuclear backgrounds of ‘Pusa kalyani’, ‘Pant toria’, and ‘Tobin’, the cultivars ‘Candle’ and ‘ATC 94211’possessed the restorer gene for this CMS in the heterozygous condition. An analysis of F₁ and F₂ generations of ‘Polima’‘Pusa kalyani’בCandle’ and ‘Polima’‘Pusa kalyani’בATC 94211’ revealed that restoration is controlled by a single dominant gene. Identification of stable maintainers and restorers of ‘Polima’ CMS could facilitate the development of hybrid varieties in B. campestris.     

Rye introgression lines as source of alleles for pollen-fertility restoration in Pampa CMS

Restoration of pollen-fertility is required to guarantee successful seed production of hybrid varieties based on cytoplasmatic male-sterility (CMS) induced by Pampa cytoplasm. As most European restorer lines have still numerous disadvantages, using genetic resources via introgression libraries might be promising to identify and localize new and more effective restorer genes. The objectives of this study were to (1) evaluate in field trials the performance of 39 candidate introgression lines (pre-ILs) for pollen-fertility restoration and (2) to identify donor chromosome segments (DCS) underlying pollen-fertility restoration. Exotic alleles from the Iranian primitive rye accession Altevogt 14160 were introduced into the elite non-restorer inbred line L2053-N by marker-assisted backcrossing. BC₂S₃ pre-ILs were genotyped using amplified fragment length polymorphisms and simple sequence repeats. Pollen-fertility restoration was evaluated in replicated field trials across two testers at two locations in 2006 for analysing the phenotypic effects of the exotic DCS. Out of 39 pre-ILs, we determined three showing full pollen-fertility across both testers and locations carrying a DCS on chromosome 4R. Moreover, one pre-IL with partial pollen-fertility was detected showing a DCS on chromosome 1R. We conclude that our introgression library can serve as a valuable resource for mining favourable genes from exotic primitive rye, which can greatly promote hybrid rye breeding.     

Development of a DNA marker for distinguishing CMS lines from fertile lines in rice (Oryza sativa L.)

The main objective of the present study was to identify mitochondrial DNA based marker, which can distinguish male sterile and fertile counterparts of the cytoplasmic male sterile (CMS) lines used in production of rice hybrids. Amplified fragment length polymorphism (AFLP) analysis in CMS lines: IR58025A & IR62829A and their respective maintainers: IR58025B & IR62829B identified a polymorphic DNA fragment of about 510 bp size that was present in both CMS (A) and absent in their maintainer (B) lines. Sequencing followed by database analysis of the polymorphic fragment indicated about 97% similarity with mitochondrial NADH gene subunits of rice, maize and wheat. Based on the variable sequence regions, a site specific primer pair (BF-STS-401) was designed. PCR analysis showed that BF-STS-401 could amplify a strong band of 464 bp size in CMS and a faint band of the same size in maintainer line. To act as a positive control and avoid possible errors in PCR, BF-STS-401 was multiplexed with a new primer pair (BF-STS-402), derived from mitochondrial atp9 subunit of rice, producing monomorphic amplification indiscriminately in both CMS and maintainer lines. Both the primer pairs in combination clearly differentiated CMS lines from their corresponding maintainer lines. This primer combination was validated in a set of diverse genotypes consisting of different sources of CMS lines, restorer lines, hybrids, varieties and mixed samples from private seed companies. Our results suggested that the multiplex primer pairs developed in this study can be effectively utilized to assess the genetic purity in commercial seed lots of CMS lines and hybrids of rice.