| Experiment was conducted in weather enclosure of Agricultural of University ofHebei during2010-2011. Six maize varieties released from1950s-Baihe(BH), Jidan101(JD), Zongdan2(ZD), Yedan13(TD), Zhengdan958(AD)and Xianyu335(XY) wereused as test materials. Lysimeters were used to study plant morphology, water useefficiency and dry matter partitionning of varieties of different eras under sufficientirrigation conditions. Maize growth bags cultivation technology was used to research theresponse of growth and development of maize varieties of different eras to water supply.The study offered basis and method for breeding of new varieties and water use efficiencyof maize verietes of different eras. The main results were should as follows.1.From1950s to2000s, the angle between stems and leaves and underground rootsspread angle all decreased. Compact plant type of overground part enhanced the lightdistribution among high density maize population, and the compact root system enabledthe use of nutrients and water in the subsoil.2.From the view of water consumption during whole growth stage, they weregradually increase for varieties from1950-1970s, yet they were reduced significantly forvariety from1980-2000s. The difference between varieties reached very significant levels(P<0.01); From the intensity of water consumption during each growth stage: it changed inthe same way among varieties of different eras during the growth period: it was the lowestduring seedling stage, and increased quickly after jointing, then peaked during tasselingand silking stage. The intensity of water consumption were declined in different way withthe different mature character during kernel filling stage: for BH of early-maturingvariety from1950s, it kernel filling stage was short so the intensity of water consumptionwas significantly less than other varieties.3.The transpiration rate (Tr) of modern varieties was significantly smaller than early’s,while the Pn did not show this trend, so the leaf water use efficiency (WUEl) appearedrising trend with the variety replacement, and the amplification of varieties after1980swere more significant than that of early varieties. Dry mass of plant increased graduallyfrom1950-1980s, and it reduced significantly for contemporary varieties. Water useefficiency calculated by dry mass per plant was peaked in1980s then decreased significantly. The grain yield per plant increased gradually during the replacement ofvarieties, the WUE by economic yield (WUEy) was appeared the trend of increasing, and itpeaked at the variety of2000s.4.The grain yield of plant showed a fast growth tendency with the veriety replacement,and the distribution of dry matter in organs showed obvious regularity: the dry matterpartitioning to ear leaf was gradually increased,which laid a foundation for transportingassimilate efficiently to grain; The dry matter partitioned to basal internodes of varietiesafter1980s was significantly higher than that of the earlys’, which illustrated thatlodging-resistance capability of modern varieties was strengthen.5. The changing rule of root length, root surface area and volume of varieties showedthe trend of first increased and then decreased: they showed an increasing tendency forvarieties in1950-1970s and they kept high levels for varieties after1980s,thoughthey reduced in different degree compared with early varieties. The modern varietiestended to lessen the amount of redundant root and still kept high absorption properties, sothe WUE was improved.6. Total root length, surface area and volume of varieties of different eras werereduced with the decreasing of soil moisture. At the same water condition, all rootcharacters of varieties after1980s were less than those of varieties in1950s-1970s’. Withthe decreasing of soil moisture all root characters were significantly decreased in0cm-10cm soil layer, while they increased in20cm-30cm soil lay. It showed that the rootsystem appeared a developing tendency to the deep soil after water supplies decreased butpromoted its function. |
PDF Full Text Request