摘要:

AbstractThe transport and distribution of14C‐sucrose and14C‐BA were studied in internode segments with ear of two winter wheat cultivars with a different mass of kernels in the period prior to anthesis. Both labelled substances were transported intensively into all the developing parts of the car, namely the rachis became the main site of14C‐BA accumulation. While the difference in the transport ofl4C‐sucrose among the cultivars was not unambiguous, a more intensive transport of14C‐BA was observed in the cultivar with a simultaneously higher mass of 1000 kernels. The higher level of zeatin and zeatin riboside in kernels detected in this cultivar suggested that in the period before anthesis it could accumulate (due to intensive transport, probably from the roots) an important part of cytokinins, available for the early stages of kernel de

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00855.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractThe effect of soybean cyst nematode (SCN) race 3 and strains ofBradyrhizobium japonkuminteractions on nodulation and other agronomic characters of several soybean genotypes was investigated. Nodule weight was reduced in soybean cultivarOgdentreated with SCN plus Bradyrhizobia strains USDA 110 and 6 and on soybean cultivarEssextreated with SCN plus strain USDA 6. The result was reversed on soybean cultivarEssextreated with SCN plus strain USDA 110. The nodule number also decreased on soybean cultivarsOgdenandEssextreated with SCN plus strains USDA 110 and 6. The fresh root weights of soybean cultivarsOgdenandEssextreated with SCN plus strain USDA 110 were heavier than the fresh root weight ofEssextreated with SCN plus strain USDA 6. Lower nitrogen content of stems and leaves was noted only in cultivarEssextreated with SCN plus strains USDA 110 and 6. Bradyrhizobia strain USDA 110 was more efficient in the initiation of nodules in cultivarsOgdenandEssexthan strain USDA 6. The nitrogen‐fixing capacity of strain USDA 6 inOgdenwas better than strain USDA 110. The differences in the agronomic performances of the various soybean genotypes were due to their degree of susceptibility to SCN and Bradyrhizobia strains and also to their genetic make

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00856.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractChanges in dry weight, osmotic potential, abscisic acid and free proline contents were measured during cold hardening of nine winter wheat varieties differing in freezing resistance. During the first weeks of cold hardening dry weight and proline levels increased and the osmotic potential decreased parallel to the development of freezing resistance. Dry weight reached a broad maximum between the seventh and tenth week of hardening. ABA levels had a sharp maximum around the seventh week of hardening, when the dry weight increase began to cease. Maximal levels of proline were observed seven to ten weeks after the start of cold hardening. The mean and final dry weights, the mean, maximal and final proline contents, as well as the maximal ABA contents of the nine varieties correlated significantly with freezing resistance measured at the end of the hardening period.The possible use of proline and of ABA as biochemical markers for freezing resistance in winter wheat breeding is discussed.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00857.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractGermplasm lines of finger millet (400 lines) with diverse genetic background were screened to identify high CER and CGR genotypes. Considerable variation was noticed in LA, biomass and all the growth and yield attributes but range in stomatal frequency was relatively less. The difference in plant stomatal number was more due to variation in LA but not the frequency. Since high TDM is a primary criteria for achieving higher grain yield, from amongst the high biomass types, genotypes differing in LA/DM ratios but with similar DM and HI were selected. In six genotypes each from low and high LA/DM group which showed stability across the environment, gas exchange characteristics were studied. The CER in low LA/DM types was 45 per cent higher. A significant negative relationship (r = ‐0.87) exists between CER and LA/DM ratios. Higher net assimilation rate in these genotypes therefore could be attributed mainly due to CER rather than the dark respiration.An approach to identify high CER types with high CGR and low plant conductances from the germplasm lines has been proposed. These conceptual types will have high CGR but with low functional LA, thus low transpiration leaf surface. These conceptual types will have specific advantage under rainfed water limited condition

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00858.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA lysimeter study was conducted to investigate how nitrogen uptake of spring wheat and oats and N leaching losses are differing when either oilseed rape or faba bean are grown as green manure. The experiment was conducted during 1982–1988, and fertilizer applied to the cereals was either farmyard manure, FYM, (6 and 12 g N/m2/year) or mineral fertilizer, MiF, at a rate of 6 g N/m2. On average of the 7 year period faba bean increased N uptake of the cereals fertilized with FYM at harvest by 3–4 g/m2. Differences between the two application rates were negligible. N‐leaching losses increased twofold when faba bean was grown instead of oilseed rape. Growing faba bean after cereals supplied with MiF, too, increased N uptake of the cereals and significantly increased leaching l

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00859.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractA factorial experiment with 3 nitrogen (N) levels and 4 application rates of the triazole type plant growth regulator (PGR), BAS 111 W = l‐phenoxy‐3‐(1H‐1,2,4‐triazol‐1‐yl)‐4‐hydroxy‐5,5‐dimethylhexane, was conducted in hydroponics to study the influence on N uptake and morphological changes of oilseed rape. The following results were obtained:–Increased N level of the nutrient solution increased plant height and root and shoot weight. Enhanced N uptake caused a higher N concentration of root and shoot.–Increasing PGR application rates reduced plant height and shoot biomass production; this reaction was stronger at higher doses of N.–Root weight, root length, root diameter and root surface area were increased by N application. None of these parameters was significantly altered by the PGR. This resulted in increased root‐shoot‐ratios at higher PGR rates.–As a consequence of reduced shoot production PGR application resulted in increased concentrations of N. The root reacted

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00860.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractWater stress was imposed by watering withholding or application of PEG during the period following ligule emergence of Hag leaves or fifth leaves. Treatment reduced markedly the downward rotation of these youngest fully expanded leaves, and the angle finally reached. Leaf angle changes appear to be sensitive indicators of water shortage in wheat.

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00861.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractField studies on differentially irrigated wheat (Triticum aestivumL.) crops were conducted at Pantnagar for two years to evaluate the use of thermal infrared radiation to detect crop water stress. Data show that the stress‐degree‐day index (mid day canopy‐air temperature difference) is influenced by environmental variability other than soil moisture. Improvement in the stress‐degree‐day (SDD) index was achieved by including the measurements of vapor pressure deficit and approach was termed as plant water stress index (PWSI). Observations indicated that daily variation in SDD values due to meteorological changes was removed through PWSI. Better correlation was found between soil‐induced leaf water potential and plant water stress index than between total leaf water potential and plant water stress index. It is concluded that remote sensing of thermal infrared radiation offers a promising technique which can be incorporated into irrigation managemen

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00862.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractOverseeding with red clover(Trifolium pratenseL.) and stocking rate are factors that can affect composition and production of hill land pasture. A grazing experiment utilizing yearling beef steers (Bos taurus)was conducted using 3, 4, and 5 yearling steers ha−1(285 kg), on native pasture (predominantlyPoa pratensisL.) overseeded with red clover and non overseeded. Paddocks of 1 ha were continuously set stocked from mid May to the end of Sept. Herbage mass, herbage consumed and the percentage of legumes, grasses, dead material, and non‐leguminous broadleaf plants were recorded. Animals were weighed at the initiation and end of each grazing season and at 4 week intervals. Overseeding increased legume content 4‐fold the seeding year but much of this increase was lost the following year. Herbage mass was greater on overseeded pasture the year following seeding but no effect on animal productivity was found. Stocking rate did not affect percentage legume but the proportions of other broadleaf plants increased at high stocking rates. Average daily gain as well as total gain ha−1was greatest at 4 stee

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00863.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY

摘要:

AbstractSolar tracking has been described in several agronomic and wild species, yet variation within a given species has not been reported. To address that issue, photoperiod leaflet reorientation in response to vectorial light was measured in three alfalfa (Medicago sativaL.) germplasm pools selected from the cultivar Ladak 65. Dark‐leaf germplasm responded to all photosynthetic photon flux densities (PPFD) (100 to 700 μmol/m2/s) with no detectable lag period. Following a 24‐h dark treatment only high PPFD (600 to 700μmol/m2/s) elicited reorientation. Pale‐leaf germplasm responded to intermediate (300 to 400 μmol/m2/s) and high PPFD in a similar manner; however, the low (100‐125μmol/m2/s) PPFD treatment had little effect on reorientation. The 24‐h dark treatment decreased reorientation at all PPFD. Small‐leaf germplasm responded equally to all PPFD and was not affected by the 24‐h dark treatment. The results suggest that available energy levels may influence the reorientation response. Carbonyl cyanidem‐chlorophenylhydrazone, an inhibitor of photophosphorylation, and 3‐(3,4‐dichlorophenyl)‐1,1‐dimethylurea, an inhibitor of non‐cyclic photosynthetic electron transport, reduced reorientation only in the pale‐leaf type. These results suggest that stored energy reserves were adequate to maintain leaflet reorientation in the absence of photosynthesis in all but the pale‐leaf germplasm. In that germplasm photosynthetically generated energy may be

ISSN:0931-2250    

DOI:10.1111/j.1439-037X.1990.tb00864.x

出版商:Blackwell Publishing Ltd    

年代:1990

数据来源: WILEY