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991.
Summary In the first part of this paper some experimental conditions necessary for a valid statistical analysis of differences in growth curves are discussed.Next the multivariate character of growth curves is considered. Data on the growth curves of three genotypes of an experiment with tomatoes of the IVT are used for illustrating the computational procedure and some aspects of interpretation.The growth curves of log dry leaf weight for each plot could be described by a quadratic function of time and were characterised by three components: mean level m, slope 1 (linear component) and curvature q (quadratic component).Univariate analyses of variance (ANOVA) showed significant differences between cultivars for each growth component: however, this is only part of the information as the correlation between the components is not involved. From a multivariate analysis of variance (MANOVA) it appeared that in this experiment the differences in growth between the cultivars were best expressed by using mean level m only.An estimate of the final (reduced) statistical model underlying the tomato example is derived.It is advised to split up growth into different phases of development each with its own analysis. At least four harvest dates for every phase seem desirable. 相似文献
992.
Summary The early growth of 96 genotypes of tomato was studied at 320 ppm CO2 and at 750 ppm CO2 in separate climate rooms. Plants were harvested at 40 and 55 days after sowing. Fresh and dry weights were determined. Large differences between genotypes were found for average plant fresh and dry weights and for relative growth rates. The average overall growth enhancement by CO2 enrichment was 2.3. Two genotypes showed significant genotype x CO2 interaction. The consequences of these results for tomato breeding are discussed. 相似文献
993.
Summary Over 7,600 durum wheat accessions belonging to 22 country gene pools were evaluated in Syria, during the seasons 1985–86 through 1987–88 under semi-arid Mediterranean climatic conditions. Data on seven agronomic traits are presented to assess the distinctiveness and the phenotypic diversity of these pools. Univariate statistical analysis revealed differences among materials of diverse origins for all traits. Mean phenotypic diversity within countries was highest in the germplasm from India, lowest in that from Bulgaria. In a canonical variate analysis, the first three canonical variables explained 77.7% of the total variance. A cluster analysis was performed to supplement the generated information by the canonical analysis. The multivariate analyses evidenced the distinctiveness of the Ethiopian germplasm. The gene pools from Syria and Jordan, closely resembling each other, appeared separate from all others. A certain peculiarity was also shown by the germplasms from Greece, Morocco and France, while the remaining countries clustered into four groups. The results of the present evaluation could provide useful information for breeding activities, germplasm collection, and establishment of core collections. Evidence is presented that environment played a major role in creating the overall variation for the considered traits, although germplasm exchange seemed also an important factor. 相似文献
994.
试验结果表明,利用植物激素能有效的诱导出杂交水稻第一代(F1)单性生殖种子。诱导时宜在早造杀雄后3-4d,采用6-BA(50mg/L)或NAA(25mg/L) 2,4-D(25mg/L)作诱导剂可提高诱导效果,增加单性生殖种子的结实率。 相似文献
995.
996.
997.
玉米花期干旱及复水对植株补偿生长及产量的影响 总被引:35,自引:0,他引:35
研究了花期干旱对盆栽玉米生长发育、生理特性和产量的影响及复水后植株的补偿生长。花期干旱使雌穗生长发育不良,产量下降,复水后被干旱所延迟的雌穗发育可以部分恢复,存在关明显的补偿生长。复水后产量的补偿表现为百粒重的增加,但这种补偿不足以弥补由于穗粒数的减少而导致的产量下降。随胁迫时间延长及胁迫强度的增加,叶片气孔阻力迅速增加,复水后气孔阻力迅速减少,胁迫强度愈大,恢复速率愈快、蒸腾速率与气孔阻力基本上 相似文献
998.
Frew Mekbib 《Euphytica》2003,130(2):147-153
An experiment was undertaken to determine the stability of seed yield in 21 common bean genotypes representing three growth
habits. Seven genotypes in each growth habit (determinate bush, indeterminate bush and indeterminate prostrate) were evaluated
in replicated trials at three locations for three years under rain fed conditions in Ethiopia. A combined analysis of variance,
stability statistics and rank correlations among stability statistics and yield-stability statistic were determined. The genotypes
differed significantly for seed yield and genotype × environment (year by location) interaction (GE). The different stability
statistics namely Type1, Type 2 and Type 3 measured the different aspects of stability. This was substantiated by rank correlation
coefficient. There were strong rank correlations among Si
2d, Wi
2,σi
2 and Si
2, where as there was weak correlation between biand Ri
2, Si
2d, Wi
2, σi
2 and Si
2. R2 was significantly and negatively correlated with Wi
2, σi
2 and Si
2. σi
2 is significantly correlated with Wi
2.Yield is significantly correlated with bi and Ri
2.None of the statistics per se was useful for selecting high yielding and stable genotypes except the YS(yield-stability statistic). Most of the high yielding
genotypes were relatively stable. Of the 21 genotypes, only 11genotypes were selected for their high yielding and stable performance.
Genotypes with growth habit III and I (in determinate prostrate and determinate bush) were generally more stable than in determinate
bush.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
999.
Growth vigour plays an important role in the establishment of a normal crop. The F2 population of a cross between high‐ and low‐growth vigour varieties of chickpea segregated into 15 high : 1 low growth vigour. The results for recombinant inbred lines and BC1P2 showed a good fit to the expected 3 : 1 ratio. The results indicated that growth vigour is controlled by two genes with duplicate dominant epistasis. No gene has so far been identified for growth vigour in chickpea. Correlation between growth vigour and other characters showed that high growth vigour had significant negative correlation with days to first flower, days to 50% flowering, days to first pod and days to maturity. 相似文献
1000.
Summary The character of determinate plant growth has not been reported for chickpea and has not been observed in the world germplasm collection at ICRISAT, Patancheru, India. A determinate growth habit would be desirable where growing conditions often lead to excessive vegetative growth. We attempted to generate this trait by mutation breeding. Seeds of the cultivar ICCV 6 were exposed to varying irradiation treatments, M1 and M2 populations were raised, and in the latter one plant was detected that showed the determinate growth habit and female sterility. The character of determinate growth segregated in a postulated digenic epistatic 3:13 fashion in the F2 and confirmed its digenic mode of inheritance in the F3 and F4. The symbol cd is proposed for the allele conditioning for determinancy and Dt for the allele expressing the determinate trait. Continued mutation breeding with this and other material may result in identifying fully fertile, determinate plant types.Abbreviations DT -
determinate
- IDT -
indeterminate
ICRISAT Journal Article No. 1396. 相似文献