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931.
水稻亲本遗传分化程度与籼粳杂种优势的关系 总被引:44,自引:2,他引:44
本文利用两套材料,即来自一个籼/粳交(圭630/02428)的双单倍体(DH)系和另一组由多种类型的籼、粳组成的对照组,从分子水平上研究了水稻亲本的遗传分化程度。在此基础上探讨了亲本的遗传分化程度与籼粳杂种优势的关系。两套测交F1群体的结果一致表明,亲本遗传分化程度对穗数和千粒重的影响相对较小,但是对每穗结实粒数和结实率这两项体现育性的指标影响较大。当亲本遗传分化综合指数TDj值为20 ̄25时,育 相似文献
932.
G. Delogu C. Lorenzoni A. Marocco P. Martiniello M. Odoardi A. M. Stanca 《Euphytica》1988,37(2):105-110
Summary The effect of a recurrent selection procedure was evaluated in a winter barley (Hordeum vulgare L.) population. Cycle zero (C0) was initiated by crossing six high yielding winter barley cultivars with the short straw cv Onice. The F1's were crossed according to a diallel scheme without reciprocals. A total of 750 S0 plants were derived and evaluated; 329 S0 plants were selected and their progenies (S1 lines) tested. Fifteen S1 lines were chosen and used as parents of cycle 1 (C1), by producing 105 F1 hybrids which simulated a random mating offspring. One hundred and three randomly chosen S1 lines belonging to C0, and 103 S1 lines belonging to C1, were evaluated at two locations.For grain yield a significant difference between cycles was observed. From C0 to C1 the grain yield increased with 307 g/m2. This increase was due to a higher number of seeds per m2. For plant height, heading date and 100-kernel weight no differences between cycles were observed.The positive results obtained in this study indicate the potential usefulness of recurrent selection for developing parents or lines superior for grain yield, with little change in other important agronomic traits. 相似文献
933.
934.
935.
棉株载铃量对其主要生育性状的影响 总被引:4,自引:0,他引:4
采用 熟性不同 的3 个陆 地棉 品种 ,在 肥水 充 足的 生 长条 件下 ,研 究了 棉 株不 同载 铃 量对其主要 生育性状 的影响 。结果表 明, 棉株 载铃 量 对株 高、果枝 总长 、果 节总 数均 有 极强 的 影响 ,其影响强 度随载 铃量的增 加而增加 ,累积 影 响量 随棉 株 生长 发 育时 间的 延 长而 增大 ;但 棉株 载 铃量对主茎 节数、果 节平均长 度影响 不显 著。 由此 分析 了 蕾铃 脱 落和 棉株 旺 长之 间的 关 系,以 及 棉株在一定 地力条 件下适宜 的单株载 铃量。 相似文献
936.
937.
沙引发对紫花苜蓿种子盐逆境下发芽及幼苗生理生化变化的影响 总被引:15,自引:3,他引:15
试验以紫花苜蓿品种维多利亚和金皇后种子为材料,研究了沙引发处理对高盐(0.8%NaCl)逆境下种子发芽及幼苗生理生化变化的影响。结果表明,沙引发处理能显著提高紫花苜蓿两个品种种子的发芽率、发芽势、发芽指数和活力指数,缩短平均发芽时间,显著增加幼苗干重,同时提高了过氧化氢酶(CAT)、超氧化物歧化酶(SOD)和过氧化物酶(POD)活性,减少丙二醛(MDA)的积累。说明沙引发提高了紫花苜蓿种子的活力和抗盐胁迫能力,促进了盐逆境下种子的萌发和幼苗生长。 相似文献
938.
药剂处理对瓜尔豆种子低温萌发和活力的影响 总被引:2,自引:0,他引:2
用不同的药剂分别在20℃、15℃条件下浸泡瓜尔豆种子24h,放入15℃的发芽箱中发芽。结果表明:400ml/kg乙烯利、10mg/kgAMP、20mg/kg6-BAl5℃浸种显著或极显著的提高种子活力,促使种子低温萌发;而20℃浸种时对种子萌发没有显著影响。0.1%水杨酸钠在15℃条件下能显著提高种子的发芽率,较长时间的维持种子活力。0.1%甲醛处理完全杀死种子。20mg/kgIAA20℃浸种、30mg/kg2,4-D15℃浸种抑制种子的萌发。200ml/kgCCC、500mg/kgGA3、0.1mol/LKNO3、25ml/kg肌醇15℃或20℃浸种效果均不明显。 相似文献
939.
Osmotic Adjustment in Maize (Zea mays L.): Changes with Ontogeny and its Relationship with Phenotypic Stability 总被引:1,自引:0,他引:1
J. H. Lemcoff C. A. Chimenti T. A. E. Davezac 《Journal of Agronomy and Crop Science》1998,180(4):241-247
Genetic variation for osmotic adjustment was examined in a group of maize hybrids during vegetative and silking stages. Estimates of osmotic adjustment were derived from measurements of leaf relative water content (RWC) and osmotic potential (Ψ o ) before day-break. The degree of adjustment was estimated from the In RWC/In Ψ o relationship. All cultivars examined showed some degree of osmotic adjustment and significant differences (P < 0.05) were found among them. The utility of measurements in early vegetative stages as a mean of selection for osmotic adjustment in silking stage was established. A positive tendency was observed between osmotic adjustment and phenotypic stability. 相似文献
940.
R. Zurayk M. Adlan R. Baalbaki M. C. Saxena 《Journal of Agronomy and Crop Science》1998,180(4):249-258
The effect of salinity on the nodulation, N-fixation and plant growth of selected chickpea- Rhizobium symbionts was studied- Eighteen chickpea rhizobial strains were evaluated for their growth in a broth culture at salinity levels of 0 to 20 dS m−1 of NaCl + Na2 SO4 . Variability in response was high. Salinity generally reduced the lag phase and/or slowed the log phase of multiplication of Rhizobium. Nine chickpea genotypes were also evaluated for salt tolerance during germination and early seedling growth in Petri dishes at five salinity levels (0–32 dS m−1 ). Chickpea genotypes ILC-205 and ILC-1919 were the most salt-tolerant genotypes. The selected rhizobial strains and chickpea cultivars were combined in a pot experiment aimed at investigating the interactive effect of salinity (3, 6 and 9 dS m−1 ) and N source (symbiosis vs. inorganic N) on plant growth. Symbiotic plants were more sensitive to salinity than plants fed mineral N. Significant reductions in nodule dry weight (59.8 %) and N fixation (63.5 %) were evident even at the lowest salinity level of 3 dS m-1 . Although nodules were observed in inoculated plants grown at 6 dS m-1 , N-fixation was completely inhibited. The findings indicate that symbiosis is more salt-sensitive than both Rhizobium and the host plant, probably due to a breakdown in one of the processes involved in symbiotic-N fixation. Improvement of salinity tolerance in field grown chickpea may be achieved by application of sufficient amounts of mineral nitrogen. 相似文献