摘要:

Dry matter accumulation and IAA level of grains in various positions within the wheat (Triticum aestivumL. cvs Solo and Kolibri) ear were investigated during the grain filling period. Main shoot ears were partitioned into basal, central and apical regions and further into proximal and distal grains. Results from a two‐year experiment with two wheat cultivars of different grain size are presented. The IAA level increased rapidly from about 8 until 20 to 30 days after anthesis, and then decreased dependent upon year and cultivar. The differences in IAA levels, both among spikelets in different regions of the ear (i.e. basal, central and apical) and also among florets within a spikelet (i.e. proximal and distal), were positively correlated with the differences in dry matter accumulation. Although the correlations held true within cultivars in a particular year, differences in dry matter between cvs Solo and Kolibri or differences from year to year were not well correlated with the corresponding changes in IAA levels. Possible interactions between dry matter accumulation and IAA levels are briefly discusse

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1985.tb02829.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

Net photosynthesis and transpiration of seedlings from shade tolerant, moderately tolerant and intolerant tree species were measured in ambient carbon dioxide (CO2) concentrations ranging from 312 to 734 ppm. The species used,Fagus grandifoliaEhrh. (tolerant),Quercus albaL.,Q. rubraL.,Liriodendron tulipiferaL. (moderately tolerant),Liquidambar styracifluaL. andPinus taedaL. (intolerant), are found co‐occurring in the mixed pine‐hardwood forests of the Piedmont region of the southeastern United States. When seedlings were grown in shaded conditions, photosynthetic CO2efficiency was significantly different in all species with the highest efficiency in the most shade tolerant species,Fagus grandifolia, and progressively lower efficiencies in moderately tolerant and intolerant species. Photosynthetic CO2efficiency was defined as the rate of increase in net photosynthesis with increase in ambient CO2concentration. When plants which had grown in a high light environment were tested, the moderately tolerant and intolerant deciduous species had the highest photosynthetic CO2efficiencies but this capacity was reduced when these species grew in low light. The lowest CO2efficiency and apparent quantum yield occurred inPinus taedain all cases. Water use efficiency was higher for all species in enriched CO2environments but transpiration rate and leaf conductance were not affected by CO2concentration. High photosynthetic CO2efficiency may be advantageous for maintaining a positive carbon balance in the low light environment under a forest can

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1985.tb02830.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY

摘要:

We have investigated the effect of pulsed nitrogen laser radiation (337.1 nm) on morphological characteristics and biochemical contents in seedlings from treated greengram (Vigna radiataL.) seeds, which were germinated and grown in Petri dishes for a week. The shoot and root lengths, and fresh and dry weights of the seedlings were maximum with the 30 min exposure, while protein was maximum with 20 min, RNA and DNA contents with 5 min exposure time. Chlorophyll content was not affected by the irradiation.

ISSN:0031-9317    

DOI:10.1111/j.1399-3054.1985.tb02831.x

出版商:Blackwell Publishing Ltd    

年代:1985

数据来源: WILEY