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91.
核桃播种育苗对比试验 总被引:1,自引:0,他引:1
试验通过核桃不同浸种时间、播种深度、播种密度的育苗对比试验,探索出了最适宜的核桃播种育苗方法,试验结果表明采用浸种10d,覆土厚度5cm,播种密度10cm×30cm,出苗率高,缩短育苗周期,增加经济收入,提高经济效益。 相似文献
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Summary Six wild barley (Hordeum spontaneum) accessions, from a diverse range of habitats, and two spring-cultivated barleys, were examined for variation in durations of development phases. The durations of the leaf initiation and spikelet initiation phases were longer and spikelet growth phases shorter, in wild than in cultivated barley. Across all wild and cultivated barleys the rate and duration of spikelet initiation were negatively correlated, but neither was related to the number of spikelets per spike. The number of spikelets was positively correlated with the number of leaves and the ratio of the number of spikelets to the number of leaves declined with increasing time to anthesis, indicating that each successive leaf was associated with a diminishing increase in the number of spikelets. The duration of culm elongation and final culm length were shorter in accessions of cultivated barley compared with wild barley. This paper also discusses the feasibility for increasing the number of spikelets per spike through breeding for genetic changes in lengths of pre-anthesis phases of development.Abbreviations ANOVA
Analysis of variance
- HV
Hordeum vulgare
- CE
Culm elongation
- DR
Double ridge
- HS
Hordeum spontaneu
- ° Cd
Degree days 相似文献
96.
The African rice Oryza glaberrima, traditionally cultivated since more than 3.500 years, is of poor agronomic performance but resistant/tolerant to various
stresses and diseases. The introduction of these characters into O. sativa cultivars is difficult since crossing barriers cause spikelet sterility in F1. Backcrossing can restore fertility and recently
facilitated the development of fertile O. glaberrima × O. sativa ssp. japonica hybrid progenies for rain fed systems. With the objective to gain access to African rice germplasm for improvement of irrigated
rice, crosses were performed with eighteen O. glaberrima and twenty O. sativa ssp. indica accessions. In total about one hundred F1-hybrid grains were obtained. The F1 plants were all completely sterile and backcrossing
(BC) to O. sativa was performed in order to restore spikelet fertility. Monitoring of Tog5681 × IR64 hybrid progenies under field conditions
revealed a broad genetic diversity within the BC1 and BC2 populations. Some BC1 and BC2 progeny plants outperformed the O. sativa parent, indicating that the heterozygocity level and complementary gene action after two backcrosses are still sufficient
to positively influence plant vigor. Spikelet fertility of progenies was highly variable, but almost complete fertility was
already observed within the BC1F2 population. High spikelet fertility was preserved in one out of two analyzed BC1F3 families and inmost of the BC2F3 families. The ability to restore spikelet fertility within few generations and the potential of the genetic diversity present
in interspecific progenies facilitates the development of plant types specifically designed for the African irrigated and
lowland environment.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
97.
Chromosomal locations and genetic relationships of tiller and spike characters in wheat 总被引:6,自引:0,他引:6
Number of tillers per plant, plant growth habit in seedling and adult stages, and spike and spikelet characters are agronomically
important features of the gross morphology of wheat. To localize to wheat chromosomes the genes for these traits, we scored
them in a set of wheat recombinant-inbred mapping lines already well genotyped with molecular markers. Quantitative-trait
analysis revealed a region near Gli-A2 (Xpsr10) on the short arm of chromosome 6A strongly affecting tiller number and the correlated trait of seedling growth habit. Genes
with opposing effects on adult plant type were localized on the short arms of chromosomes2A and 3A, while genes affecting
spike development were assigned to several A- and B-genome chromosomes. None of these genes showed synteny with counterpart
QTLs reported to affect the same traits in rice. In the chromosome 2D region containing the photoperiod-insensitivity gene
Ppd-D1, the major determinant of heading date in these autumn-sown lines, earliness alleles reduced tiller and spikelet numbers
and increased erect seedling growth habit, but showed no influence on adult plant type or spike length. Though several of
these morphological traits are generally considered to be associated with winter hardiness and their phenotypic intercorrelations
were consistent with the genetic mapping evidence, no association was found between newly identified loci and known vernalization-response
or frost-resistance loci.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
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