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991.
992.
云南省楚雄州自然分布(少数几种为栽培)的双子叶植物有2939种(含种以下单位),隶属170科914属。本文对其区系成分进行了统计分析,结果表明双子叶植物科的分布类型主要是以热带——亚热带分布型(41科,占24.18%)和热带——温带分布型(31科,占18.24%)为主。属的分布类型主要以泛热带分布型(243属,占26.59%)、东亚分布型(112属,占12.25%)和北温带分布型(94属,占10.28%)为主。楚雄州双子叶植物区系特征有以下显著特点:①植物种类丰富;②区系成分复杂、起源广泛;③热带、亚热带成分突出。 相似文献
993.
冬小麦不同株型品种光谱响应及株型识别方法研究 总被引:5,自引:0,他引:5
以直立和平展2种株型的冬小麦品种为材料,研究了它们的光谱响应以及田间植被覆盖度的差异,探讨了利用冠层光谱反射率、光谱特征参量NDVI及植被覆盖度识别小麦株型的方法。结果表明,(1)小麦不同株型品种在近红外波段(700~1300 nm)光谱反射率有明显差异,生育前期平展型品种高于直立型品种,并以拔节期的差异为最显著,随着生育进程差异逐渐变小。拔节期是进行株型识别的最佳时期,并且此期冠层的敏感波段680 nm和760~900 nm的反射率在2种株型品种之间差异明显。(2)小麦冠层叶面积指数(LAI)与归一化差异植被指数NDVI(680,890)呈正相关,并且不同生育阶段其相关程度有差异,这是利用NDVI和植被覆盖度(COV)识别不同株型的基础。(3)相同COV条件下,直立型品种的NDVI高于平展型品种的NDVI,并且随着COV的增加,差异逐渐变小,二者的变化关系体现了直立型品种株型紧凑和平展型品种株型披散的特点,利用NDVI和COV的关系可以对株型进行识别,以小麦拔节期为最佳识别阶段,此期2种株型品种的NDVI具有显著差异(P<0.05)。 相似文献
994.
Expression of nucleolus, endosperm storage proteins and disease resistance in an amphiploid between Aegilops tauschii and Secale silvestre 总被引:1,自引:0,他引:1
Cytology and gene expression of an amphiploid between Aegilops tauschiiL., native to China, and Secale silvestre L. were studied to reveal the genomic interaction between the donor species. High frequencies of aneuploids were observed
in the progenies of the amphiploid, indicating its cytological instability. Feulgen staining and Giemsa-C banding showed that
only the nucleolar organizing region from chromosome 5D of Ae. tauschii existed in the amphiploid (2n = 28). The nucleolus of S. silvestre was not observed. Endosperm storage protein electrophoresis indicated most gliadin and glutenin genes from both parents were
expressed in the endosperm of the amphiploid. When inoculated by wheat stripe rust and powdery mildew isolates,the amphiploid
did not express the resistance from its Secale parent,suggesting the presence of disease resistance suppressor(s) in the D genome of Ae. tauschii as well as nucleolar organizer suppressors.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
995.
以辣椒细胞质雄性不育系9704A和8214A为试材,取无菌苗真叶进行培养。研究了不同浓度的IAA,6-BA和GA3对不定芽的诱导和伸长作用,结果表明:MS+6-BA5.0 mg/L +IAA1.0 mg/L有利于不定芽的诱导。MB+IAA1.0 mg/ L +6-BA3.0 mg/L + GA32.0 mg/L +AgNO310.0 mg/L有利于芽的伸长。将2.0 cm以上的芽转入生根培养基诱导不定根发现:1/2Ms+IAA0.3~0.5 mg/L有利于不定根的诱导。 相似文献
996.
棉花黄萎菌拮抗菌BDT-25的鉴定及抗菌蛋白产生条件研究 总被引:12,自引:2,他引:12
拮抗细菌BDT_25是从根际土壤中分离到的一株对棉花黄萎病菌具有强烈抑制作用的芽孢杆菌。经生理生化特征的鉴定,证明BDT_25菌株为枯草芽孢杆菌(Bacillus subtilis)。此外,该菌株还对棉花枯萎病菌、棉花立枯病菌等10种其他病原真菌的生长具有显著的抑制作用,为一株广谱拮抗细菌菌株。通过对BDT_25菌株培养条件的研究发现,采用NB液体培养基,28℃,170 r/min培养48 h所得发酵液对棉花黄萎病菌的抑制作用最强。其发酵液经硫酸铵沉淀粗提到对棉花黄萎病菌具有抑制作用的提取物,进一步实验表明,该拮抗物质对热和多种蛋白酶敏感,证实其为抗菌蛋白。 相似文献
997.
Grain protein concentration (GPC) is an important quality factor in durum wheat [Triticum turgidum (L.) var. durum]. Due to the strong environmental influence on GPC, molecular markers linked to quantitative trait loci (QTL) affecting GPC have the potential to be valuable in wheat breeding programs. Various quantitative traits in a population of 133 recombinant inbred chromosome lines were studied in replicated trials at three locations in North Dakota. Segregation for GPC, 1000-kernel weight, gluten strength, heading date, and plant height was observed. By relating phenotypic data to a linkage map obtained from the same population, three QTL affecting GPC, and one affecting yield were identified. The genotypic coefficients of determination for both traits were high. 相似文献
998.
Summary Relationships among the traits protein percentage, grain yield, and protein yield of oats were studied with F2-derived lines in F3 and F4 from 27 matings obtained by crossing high-protein with high-yield oat lines. High-protein parents were (a) selections from an Avena sativa bulk, (b) selections from three-way matings in which an initial parent was A. sterilss, and (c) cultivars. High-yield parents were derived from backcross populations involving A. sterilis accessions as donor parents.Significnnt genetic variation existed among F2-derived lines for grain and protein yield in all matings and for protein percentage in all but one mating.Protein percentage had a highly significant negative correlation with grain yield (r=–0.33**) when pooled over all matings, but in five, these two traits were not correlated. Overall, protein percentage showed a small negative correlation with protein yield (r=–0.09*), and protein and grain yields had a high positive association (r=0.98**). F2-derived lines with both high protein percentage and high grain yield were obtained.High transgressive segregates for protein percentage occurred in two matings, for grain yield in nine, and for protein yield in 14. Most high transgressive segregates for protein yield were high because of high grain yield only, but in four matings, lines were found where protein yield was increased by concurrent increases in both protein percentage and grain yield.Only a few specific parental combinations between high-protein and high-yield parents produced segregates in which increased protein percentage contributed materially to high-protein yields.Journal Paper No. J-11264 of the Iowa Agriculture and Home Economics Experiment Stn., Ames, Iowa 50011. Project 2447. 相似文献
999.
Summary Gene action and heritability of groat protein percentage were determined in F1, F2, and F3 generations of nine crosses between three Avena sativa L. cultivars and three A. fatua L. selections. Relationships among groat protein percentage, grain yield, and 100-seed weight also were evaluated. The three A. sativa parents were Dal (high grain yield and intermediate groat protein percentage), Goodland (low grain yield and high groat protein percentage), and Stout (high grain yield and low groat protein percentage). The three A. fatua parents were chosen for the study on the basis of vigorous plant growth and high groat protein percentage. The study was conducted at Madison, Wisconsin in 1979 and 1980.There was partial dominance towards low groat protein percentage. Narrow sense heritability estimates for groat protein percentage were low in Dal and Goodland crosses and intermediate in Stout crosses. In the F2 generation, groat protein percentage was significantly higher in shattering than in nonshattering plants in 1979, but not in 1980. There were significant, positive correlations between groat protein percentage, 100-seed weight, and grain yield in F1 and F2 generations, but they were not large numerically. Relationships among these traits were either negative or nonsignificant in the F3 generation. Although our results indicated that selection for higher groat protein percentage is possible when a low protein A. sativa cultivar is used, most of our simple cross progenies from A. sativa x A. fatua crosses had weak straw and were susceptible to crown rust (Puccinia coronata
Cda. var. avenae
Fraser and Led.). 相似文献
1000.
以垦农4号为试验材料,利用垂直板发芽试验研究了化控种衣剂 (HK)和常规种衣剂(ND)对大豆幼苗侧根原基发生的影响,并对侧根原基发生过程中植物内源激素含量的动态变化进行了相应的分析。结果表明:(1)种衣剂包衣后,侧根原基发生区长度明显比对照(不包衣的种子为对照,用CK表示)增加,从大到小依次为:HK>ND>CK;(2)种衣剂处理加快了侧根原基的发生进程,总的趋势是HK>ND>CK,经F检验表明,处理和对照差异极显著;(3)侧根原基的发生状况与侧根原基发生区内源激素的含量有一定的关系,侧根的发生是几种植物内源激素相互协调、综合作用的结果,其中生长素类物质在诱导侧根原基的发生过程中起主导作用;(4)应用种衣剂可以提高侧根原基发生的数量,缩短侧根原基的发生时间,其中以化控种衣剂效果最好。 相似文献