Breeding lines with neutral genes to improve fertility of intersubspecific hybrid rice

Since the sterility neutral allele S5n has been incorporated into indica or japonica varieties, many intersubspecific hybrids have been released commercially. These hybrids showed high heterosis, but some of them exhibited unstable seed setting rate under low temperature.When the hybrids flowered at low temperature, the fertility of female gamete was normal but the pollen showed sterile. To improve the stability of fertility, the effect of pollen sterility neutral gene was studied for intersubspecific hybrids.     

亚种间杂交水稻低结实率的生理原因分析

比较了亚种间杂交稻"W6154S×培C3111"、品种间杂交稻"W6154S×特青"和常规稻"特青"的籽粒灌浆过程中生理活性变化和结实率情况.结果表明所有供试组合(品种)的强势粒对弱势粒都具有较强的抑制作用,表现在灌浆初期弱势粒的细胞色素氧化酶活性低丽IAA氧化酶活性高,直至强势粒灌浆接近完成时,弱势粒的细胞色素氧化酶活性升高、IAA氧化酶活性降低.尤其是亚种间杂交水稻的强势粒对弱势粒的抑制作用最强,导致弱势粒灌浆不充实成为秕粒,甚至发育停止成为受精空粒.亚种间杂交稻的秕粒率、受精空粒率和未受精率分别为16.86%,15.55%和6.55%,而品种间杂交稻和常规稻上述三种比率分别为12.29%,3.03%,4.70%和6.75%,2.88%,5.09%.     

两系亚种间与品种间杂交稻籽粒充实度的比较研究

对两系杂交水稻的２０个亲本材料、２１个品种间杂种材料和５３个亚种间杂种材料籽粒充实度方差分析结果表明：各类材料的籽粒充实度间的差异都达到极显著水平：谷粒充实率的变异系数为：两系亚间间杂种Ｆ１最大,亲本材料次之,两系品种间杂种Ｆ１最小;亲本材料的平均谷粒充实率显著小于亚种间杂种Ｆ１和品种间杂种Ｆ１的平均谷粒充实率,亚种间杂种Ｆ１的平均谷粒充实率与品种间杂种Ｆ１的平均谷粒充实率的差异不显著,并对解决两系灿粳亚种间杂交稻籽粒充实不良的途径进行了讨论。     

Preliminary study on the genes related to the fertility of indica/japonica hybrid rice

Studying the sterility of indica/japonica hybrid was a prerequisite for the utilization of heterosis in high yield rice breeding. In 1986, Ikehashi et al found that wide compatibility varieties, which possessed S5-n allele, couldovercome the sterility of indica/japonica hybrids, and thesterilitv was mainly caused by allelic interaction at S-5 lo-cus. Further studies indicated that the sterility could notbe completely overcome just by S5-n. There were must beother loci responsible for the sterility of indica/ japonicahybrids.     

Ⅱ优辐819与两优培九在不同肥力土壤试验初报

通过Ⅱ优辐819与两优培九在不同肥力的土壤上进行的对比栽培试验，说明了Ⅱ优辐819在闽北有更高的生态适应性和推广价值，并制定相应的高产栽培技术提供生产上利用。     

Super hybrid rice

Ｕｐｔｏｎｏｗ,ｔｈｅｒｅａｒｅｏｎｌｙｔｗｏｅｆｆｅｃｔｉｖｅｗａｙｓｔｏｉｎｃｒｅａｓｅｔｈｅｙｉｅｌｄｐｏｔｅｎｔｉａｌｏｆｃｒｏｐｓｔｈｒｏｕｇｈｂｒｅｅｄｉｎｇ,ｉ．ｅ．ｍｏｒｐｈｏｌｏｇｉｃｉｍｐｒｏｖｅｍｅｎｔａｎｄｈｅｔｅｒｏｓｉｓｕｔｉｌｉｚａｔｉｏｎ．Ａｃｔｕａｌｌｙ,ｔｈｅｐｏｔｅｎｔｉａｌｉｓｖｅｒｙｌｉｍｉｔｅｄｂｙｕｓｉｎｇｍｏｒ ｐｈｏｌｏｇｉｃｉｍｐｒｏｖｅｍｅｎｔｏｎｌｙ,ａｎｄｈｅｔｅｒｏｓｉｓｂｒｅｅｄｉｎｇ ｗｉｌｌｐｒｏｄｕｃｅｕｎｄｅｓｉｒａｂｌｅｒｅｓ…     

Super hybrid rice

Up to now, there are only two effective ways to increase the yield potential of crops through breeding, i.e. morphologic improvement and heterosis utilization.     

杂交稻新组合作再生稻筛选试验初报

引进8个新组合种植对比试验,以Ⅱ优航1号作对照.结果表明:产量、抗性、综合性状等表现比Ⅱ优航1号好的有扬两优6号、天优3229、谷优3301.适宜在尤溪县作再生稻推广种植.     

优质晚稻新组合试验初报

2006年晚季引进6个米质均达国家二级米以上的优质晚稻新组合进行对比试验,结果表明:宜香优673、宜香优2292、甬优6号等3个组合比当家组合Ⅱ优1273产量高、抗性强、生育期适中,适宜上杭县珊瑚乡作烟后稻栽培种植。     

杂交水稻高产施氮量的研究

氮素是水稻三大营养元素之一.推广杂交水稻和增施氮肥,被认为是近期水稻大幅度增产的两大主要因素.据联合国粮农组织(FAO)统计,我国1995～1997年水稻平均单产6.18t/hm2,氮素化肥施用量180kg/hm2.但是,一些地区存在施氮量偏多,引发环境污染的趋势.为了探索杂交水稻高产的施氮量,开展本试验.     

Male fertility and 2n pollen production in haploid-wild species hybrids

Hybrids (2n = 2x = 24) from crosses between Group Tuberosum haploids (2n = 2x = 24) and 24-chromosome, wild species must be fertile and produce 2n gametes if they are to be used in breeding schemes involving sexual polyploidization. Male fertility of the 2x hybrids depends primarily on the species parent. Hybrids involvingS. berthaultii, S. chacoense, S. kurtzianum, S. spegazzinii, andS. tarijense as parents are male fertile. The haploid parents are male sterile, so the species not only contribute genetic diversity and desirable traits, but also genes necessary for male fertility.S. infundibuliforme, S. raphanifolium, andS. sanctae-rosae parents produced male sterile hybrid progeny, while use ofS. boliviense, S. bukasovii, S. canasense, S. microdontum, andS. sparsipilum results in families containing both fertile and sterile plants. Sterility may be due to interactions between Tuberosum cytoplasm and dominant nuclear genes from the species. Genetic male sterility and environmental conditions may also be responsible for low pollen stainability in some hybrids. Many fertile, 2x hybrids produce 2n pollen. Selection for 2n pollen in the species is fast and efficient, but meiotic analysis is required in male sterile haploids. Fortunately, selection in the species parent alone results in a large number of 2n pollen-producing hybrids. These 2x hybrids have been used to generate tetraploids via 4x × 2x crosses.     

Higher yields of hybrid rice do not depend on nitrogen fertilization under moderate to high soil fertility conditions

Background

Increasing rice yield with fewer external inputs is critical to ensuring food security, reducing environmental costs, and improving returns. Use of hybrid rice has expanded greatly in China due to its higher yield potential. Meanwhile, large and increasing amounts of nitrogen (N) fertilizers have been used for expanding rice production in China. It is not clear to what extent the success of hybrid rice in China is associated with N fertilizer inputs.

Findings

We observed that the higher grain yield with N fertilizer in hybrid rice was driven more by a higher yield without N fertilizer than by increases in grain yield with N fertilizer under moderate to high soil fertility conditions.

Conclusions

Our results suggest that greater application of N fertilizers is not needed to benefit from hybrid rice production under moderate to high soil fertility conditions, and that improving and maintaining soil fertility should be a focus for sustaining hybrid rice production. Moreover, our study also indicates that zero-N testing may be a potentially useful tool to develop hybrid rice with high yield and without requirement of greater external N inputs under moderate to high soil fertility conditions.

     

福优325高产制种技术

福优325是恩施州红庙农科所用福建省农科院稻麦研究所选育的福伊A与自育的恢复系恩恢325配制而成的高产抗病、米质中上、适应性广的迟熟籼稻新组合。2001年11月通过恩施州农作物品种审定小组审定,2003年11月通过国审(审定编号：国审稻2003070)。2000～2003年4a在恩施州及周边的低山稻区累计推广种植约4．5万     

水稻杂糯间作栽培增产技术

水稻是四川主要粮食作物之一 ,常年种植面积220万hm2左右 ,占粮食播种面积的30% ,总产量170亿kg左右 ,占全年粮食总产的50 %。糯稻是水稻生产重要组成部份 ,糯米是传统的食品加工和酿酒业不可缺少的原料 ,在人们生活中占有十分重要的地位。20世纪80年代末期 ,四川省杂交水稻大面积推广 ,籼稻产量大幅度提高 ,而糯稻生产却相对落后 ,一是品种老化 ,多为常规品种 ,虽然品质较优 ,但秆高 ,抗性较差 ,二是栽培落后 ,生产上均以净作方式栽培 ,易于倒状 ,特别是近10年来水稻稻瘟病危害呈加重发展趋势 ,糯稻单产仅350kg/667m2左右 ,导致经济效益不…     

杂交稻新组合再生力比较试验初报

为了筛选出适宜尤溪县栽培的高产、抗病、再生力强和米质优的再生稻新组合,2008年尤溪县农技站与梅仙镇农技站合作,选用米质较优,产量高和抗性强的12个组合,在梅仙镇下保村作再生稻简比试验,现将试验情况与产量结果小结如下.     

甬优6号作单季晚稻栽培的移栽密度与施氮技术研究

选择了移栽密度、追肥纯氮用量及其在各处理用量下,纯氮在分蘖肥和保花肥上的分配比例等3个试验因子,采用单形格子设计,布置田间参数试验,建立了3个供试因子对产量的回归数学模型,经对模型的解析,并结合生产实际认为,甬优6号的移栽密度为0.95万丛/667m2左右,追肥纯氮用量10.5 kg/667m2左右,其中移栽后10d以65%左右的用量作分蘖肥,在主茎倒2叶露尖时,以35%左右的用量作保花肥施用为宜.