“十二五”以来,我国水稻审定品种数量快速增加,结构类型逐步优化;杂交稻制种面积波动明显,制种结构不断优化;种子市场价格稳步上涨,市场规模不断扩大;大面积推广品种数量和面积双减,品种优质率明显提升;水稻种子出口贸易量窄幅波动,贸易金额稳步增长。但同时,我国水稻种业发展也面临育种创新能力有待增强、企业竞争力有待提升、种子生产水平有待提高、杂交稻种子出口有待扩大等问题与挑战。从未来发展看,生物育种等新技术将加速发展,突破性新品种将加快推广应用,种子市场集中度将持续提升,杂交稻国际战略将从产品输出向技术输出转变。

【目的】 从水稻稻瘟病抗性的机理、抗性基因的定位、克隆以及抗性基因在育种中的应用,为水稻抗性基因的鉴定和抗性育种提供参考。【方法】 汇总和对比分析国内外的相关文献,分析不同抗性基因在水稻抗稻瘟病中的应用研究进展。【结果】 已有大约100个抗性基因被鉴定出和500个抗病基因相关的数量性状位点;在水稻基因组中被鉴定和定位的基因中,已有37个基因被成功克隆;在不同的育种方法中,基因工程育种是水稻稻瘟病抗性育种中最直接的方法。【结论】 水稻稻瘟病抗性基因的鉴定是抗性育种的基础,抗性基因的充分利用有利于快速有效的选育出新的具有广谱和持久抗性的抗病品种。

Blast is arguably the most devastating fungal disease of rice. Systematic studies of this disease have made significant progress and identified many genes. Broad-spectrum resistance is highly preferred in agricultural practice. Here, we focus our discussion on resistance (R) and defense-regulator (DR) genes that confer broad-spectrum resistance to Magnaporthe oryzae, in particular those potentially causing no significant yield penalties. Recent advances show that broad-spectrum resistance can be achieved without significant yield penalties, or even with yield benefits. Cross talks of defense signaling mediated by these genes are present that may allow the host to integrate different anti-fungal factors against M. oryzae infection. We also summarize possible mechanisms underlying broad-spectrum resistance to rice blast.Copyright © 2019 The Authors. Published by Elsevier Ltd.. All rights reserved.

The tobacco N gene confers resistance to Tobacco mosaic virus (TMV) and encodes a toll-interleukin-1 receptor/nucleotide binding/Leu-rich repeat class protein. Recent evidence indicates that the Nicotiana benthamiana Rar1 gene (NbRar1), which encodes a protein with a zinc finger motif called CHORD (Cys- and His-rich domain), is required for the function of N. To investigate the role of NbRar1 in plant defense, we identified its interaction partners. We show that the NbRar1 protein interacts with NbSGT1, a highly conserved component of the SCF (Skp1/Cullin/F-box protein)-type E3 ubiquitin ligase complex involved in protein degradation. In addition, we show that NbSGT1 interacts with NbSKP1. Suppression of NbSGT1 and NbSKP1 shows that these genes play an important role in the N-mediated resistance response to TMV. Both NbRar1 and NbSGT1 associate with the COP9 signalosome, another multiprotein complex involved in protein degradation via the ubiquitin-proteasome pathway. Silencing of the NbCOP9 signalosome also compromises N-mediated resistance to TMV. Our results reveal new roles for SCF and the COP9 signalosome in plant defense signaling.

Rice is a staple food crop in the world. With the increase in world population and economic development, farmers need to produce more rice in limited field. However, the rice production is frequently affected by biotic and abiotic stresses. The use of natural disease resistance and stress tolerance through genetic breeding is the most efficient and economical way to combat or acclimate to these stresses. In addition, rice with aromatic fragrance can significantly increase market value for its good grain quality. Mianhui 725 (MH725) is an elite restorer line that has been widely used to produce three-line hybrid rice in China. We previously introduced rice bacterial blight resistance genes Xa4 and Xa21 into MH725 and obtained an introgression rice line Wanhui 421 (WH421), which theoretically possesses 96.9% genetic background of MH725. Here we report the introduction and pyramiding of disease resistance genes Xa27 and Pi9, submergence tolerance gene Sub1A and aromatic fragrance gene badh2.1 in WH421 through backcrossing and marker-assisted selection. The newly developed introgression rice line was designated as Wanhui 6725 (WH6725), which theoretically possesses 95.0% genetic background of MH725. WH6725 and its hybrid rice conferred disease resistance to both blast and bacterial blight diseases and showed tolerance to submergence for over 14 days without significant loss of viability. Compared with non-aromatic rice MH725, WH6725 has strong aromatic fragrance. The major important agronomic traits and grain quality of WH6725 and its hybrid rice obtained in field trials were similar to those of MH725 and the control hybrid rice, indicating that WH6725 is as good as MH725 when it is used as a restorer line for three-line hybrid rice production. We have successfully developed a new restorer line WH6725 with disease resistance to rice blast and bacterial blight, tolerance to submergence and aromatic fragrance, which can be used to replace MH725 for hybrid rice production.

简要介绍了豫南稻区“籼改粳”的基本情况和在理论技术方面的研究进展。高温、稻瘟病和纹枯病、三代三化螟危害是豫南粳稻产量低、品质差的三大障碍因子，而播期早是产生障碍的根源，推迟粳稻播期是“籼改粳”的关键技术；豫南“籼稻-小麦”轮作存在制度缺陷，推迟粳稻播期可以得到修复，因秧龄过长而减产、机插秧以及抛秧难以利用等问题得到解决；增产提质、机械化、轻简化、规模化生产是“籼改粳”的必然选择；“东粳西移”是解决豫南粳稻品种利用的有效途径；机插秧、抛秧有利于实现粳稻推迟播种，而“泥质法”育秧解决了高温条件下育秧的问题，提高了机插秧、抛秧的秧苗素质；粳稻晚播稻瘟病、纹枯病和三化螟已不再是豫南“籼改粳”的毁灭性病虫害，恶苗病、干尖线虫病、稻蓟马、稻曲病上升为主要病虫害；水稻两段栽培技术是根据水稻高产稳产生长发育规律，分别从群体、形态和机能构建三个方面进行栽培设计，按照营养生长和生殖生长两个阶段进行定向培育的一种栽培方法，不仅高产稳产，而且减肥减药。

1豫南优质稻米开发的现状

北粳南移在江西省已推行11年,为进一步明确适合江西晚粳常规稻的稻瘟病抗性情况及粳渗籼骨干亲本的选择,本研究利用Pi37/Pi35/Pish、Pi5、Pi2、Pi9、Pia、Pi23、Pigm、Pi33/Pi42、Pi56、Pik/kg(t)/ks/kp/km/kh/43、Pikh共11个抗瘟基因的标记结合井冈山抗性谱的鉴定,对28份骨干粳稻和54份骨干籼稻进行分子标记与抗性分析。结果表明,粳稻中有1份携带其中的7个抗性基因,有5份携带6个抗性基因,有7份携带5个抗性基因,有12份携带4个抗性基因,有3份携带3个抗性基因,抗性频率最高的Pia为0.786,其次为Pikh和Pi9,频率均为0.643,Pigm和Pi37/Pish在这批粳稻材料中的抗性频率为0;籼稻中有8份携带其中的7个抗性基因,有10份携带6个抗性基因,有13份携带5个抗性基因,有17份携带4个抗性基因,有4份携带3个抗性基因,有2份携带2个抗性基因,抗性频率最高的Pi9为0.981,其次Pik/Pikh/Piks频率为0.833,Pigm、Pi37/Pish、Pikh、Pia、Pi5、Pi2、Pi23和Pi33/Pi42的频率分别为0.556、0.537、0.519、0.389、0.352、0.315、0.167和0.111,Pi56在这批籼稻材料中的抗性频率为0。明确这些材料抗瘟基因的分布,将为广谱持久抗性籼粳材料创制骨干亲本的选择与配组指明了方向。

为了明确勐海县水稻主栽品种中已克隆的Pi2、Pi9、Piz-t、Pi50/Pigm、Pita-2和Pib等6抗稻瘟病基因的构成。通过对勐海县18个水稻主栽品种为试验材料，利用6个抗病基因的特异分子标记进行抗瘟基因的分子检测。结果显示：抗性基因Pib分布频率最高，检出率为77.78%，Pi2、Pita-2和Piz-t的检出率分别为22.22%、22.22%和11.11%；在供试品种中未检测出抗性基因Pi9和Pi50/Pigm基因。检测到2个抗性基因和1个抗性基因的品种均为8份（均占44.44%），未检测出抗性基因的品种为2份（占11.11%）。结果表明：勐海县水稻主栽品种的抗性遗传背景较为狭窄，需引入新的有效抗源以拓宽水稻品种的抗病性。

稻瘟病是世界上影响水稻(Oryza sativa)粮食生产的主要病害之一, 抗病基因的发掘与利用是抗病育种的基础和核心。随着寄主水稻和病原菌稻瘟病菌(Magnaporthe oryzae)基因组测序和基因注释的完成, 水稻和稻瘟病菌的互作体系成为研究植物与真菌互作的模式系统。该文对稻瘟病抗病基因的遗传、定位、克隆及育种利用进行概述, 并通过生物信息学分析方法, 探讨了水稻全基因组中NBS-LRR类抗病基因在水稻12条染色体上的分布情况, 同时对稻瘟病菌无毒基因的鉴定及无毒蛋白与抗病蛋白的互作进行初步分析。最后对稻瘟病抗病基因研究存在的问题进行分析并展望了未来的研究方向, 以期为水稻抗稻瘟病育种发展和抗病机制的深入理解提供参考。