1,860 research outputs found
Growth and yield response of barley and chickpea to water stress under three environments in southeast Queensland. II. Root growth and soil water extraction pattern
Root growth and water extraction of two barley cultivars, Corvette (early maturing), Triumph (late maturing) and one cultivar of chickpea (Amethyst at Redland Bay and Borwen at Hermitage) were compared under three environments: April sowing and July sowing at Redland Bay and June sowing at Hermitage Research Station, south-east Queensland. This work was designed to explain differences in dry matter production in terms of root growth and water uptake during the crop growth, which relied only on stored soil moisture. In the April sowing where all crops grew well during the early stages of growth, decline in soil water with time for the whole profile was similar among all crops. In the winter sowings (June, July), total water use was less in chickpea than in barley, particularly during early stages when chickpea growth was poor. Water extraction patterns of two barley cultivars were similar in all experiments, though the late-maturing Triumph extracted slightly more water than early maturing Corvette towards maturity. Water extraction front velocities of the three crops were similar in each experiment. At Redland Bay, the water extraction front velocities varied from 1.4 to 1.6 cm day-1 in the April sowing and 2.3 to 2.4 cm day-1 in the July sowing, while they varied from 2.0 to 2.3 cm day-1 at Hermitage. However, descent of the water extraction front commenced later in chickpea than in barley when sown in winter months, and this resulted in lower total water use in chickpea, particularly at Hermitage. In both sowings at Redland Bay total root length increased rapidly to about 60 days after sowing in barley, whereas the increase was slower in chickpea. Root length density was high in the upper soil layers, and this was associated with high extractable soil water. In deeper layers both root length density and extractable soil water decreased. For a given root length density chickpea extracted more water than barley. These results indicate that the differences in root growth and water extraction by the two barley crops were rather small and were unlikely to be the reason for the differences in total dry matter production. Chickpea on the other hand appeared to be susceptible to low temperatures during early stages of growth, and this caused poor growth of both shoots and roots
Retrieval Properties of Hopfield and Correlated Attractors in an Associative Memory Model
We examine a previouly introduced attractor neural network model that
explains the persistent activities of neurons in the anterior ventral temporal
cortex of the brain. In this model, the coexistence of several attractors
including correlated attractors was reported in the cases of finite and
infinite loading. In this paper, by means of a statistical mechanical method,
we study the statics and dynamics of the model in both finite and extensive
loading, mainly focusing on the retrieval properties of the Hopfield and
correlated attractors. In the extensive loading case, we derive the evolution
equations by the dynamical replica theory. We found several characteristic
temporal behaviours, both in the finite and extensive loading cases. The
theoretical results were confirmed by numerical simulations.Comment: 12 pages, 7 figure
Four gene introduction methods affect the shoot regeneration and localization of transgene expression in greenhouse stem explants and in vitro-grown chrysanthemum stem thin cell layers
Gene introduction method (GIM) affected shoot regeneration capacity (SRC) in standard and spray-type chrysanthemums. SRC was both cultivar and GIM-dependent in both in vitro and greenhouse stem explants, the former significantly higher than the latter. Sonication had an SRC-stimulating effect on in vitro explants. Other GIMs (Agrobacterium, biolistics, Agrolistics) had an SRC-inhibiting effect on greenhouse explants. Genotype-dependence of SRC was observed in both in vitro and greenhouse material. SRC is influenced by the explant and regeneration media, which should be modified if altered by the GIM. Shoots derived from all GIM treatments showed normal growth under in vitro and greenhouse conditions, and flowered normally. In addition, this study further shows that explant origin (in vitro versus greenhouse) and cultivar significantly affect the regeneration process, even when an optimized medium is utilized. The integration of the GUS transgene is also GIM-dependent, but in all cases is shown to occur in the venation.
(African Journal of Biotechnology: 2003 2(5): 114-123
Respon Tanaman Kacang-Kacangan yang Bersifat Determinate dan Indeterminate pada Berbagai Kondisi Ketersediaan Air
Growth and yield of soybean and blackgram, having determinate and indeterminate in flowering respectively, were compared under three water regimes. Under well-watered conditions, blackgram continuously produces flowers where under rainfed + irrigation and rainfed condition, two periods of flowering can be distinguished. While only one period of flowering was observed in soybean. The second flush of flowering of blackgram in rainfed and rainfed + irrigation areas occurred during high rain fall. Partial irrigation as much as 80 mm toward the end of pod filling in soybean did not give benefit to soybean, but irrigation stimulate flowering in blackgram and increase yield up to 25%. Thus indeterminate behavior might give higher yield under rainfed condition due to its flexibility of flowering
Estimation of responses of yield and grain protein concentration of malting barley to nitrogen fertiliser using plant nitrogen uptake
The effect of nitrogen application on the grain yield and grain protein concentration of barley was studied in 13 field trials covering a wide range of soil N conditions over 4 years at locations in south-eastern Queensland. The main objectives of the study were to quantify the response of barley to N application rate over a range of environmental conditions, and to explain the response in terms of soil mineral N, total N uptake, and N distribution in the plants. Barley made efficient use of N (60 kg grain/kg N) until grain yield reached 90% of maximum yield. Grain protein concentration did not increase to levels unacceptable for malting purposes until grain yield exceeded 85–90% of maximum yield. Nitrogen harvest index was generally high (above 0·75), and did not decrease until the total N supply exceeded that necessary for maximum grain yield. Rates of application of N for malting barley should be determined on the basis of soil analysis (nitrate-N) to 1 m depth and 90% of expected maximum grain yield, assuming that 17 kg N is taken up per tonne of grain produced. It can further be assumed that the crop makes full use of the nitrate N to 1 m present at planting, provided the soil is moist to 1 m. A framework relating grain yield to total N uptake, N harvest index, and grain N concentration is presented. Further, total N uptake of fertilised barley is related to N uptake without fertiliser, fertiliser application rate, and apparent N recovery. The findings reported here will be useful in the development of barley simulation models and decision support packages that can be used to aid N management
The Cgl1281-encoding putative transporter of the cation diffusion facilitator family is responsible for alkali-tolerance in Corynebacterium glutamicum
The original publication is available at www.springerlink.com.ArticleARCHIVES OF MICROBIOLOGY. 190(5): 531-538 (2008)journal articl
Robustness of the noise-induced phase synchronization in a general class of limit cycle oscillators
We show that a wide class of uncoupled limit cycle oscillators can be
in-phase synchronized by common weak additive noise. An expression of the
Lyapunov exponent is analytically derived to study the stability of the
noise-driven synchronizing state. The result shows that such a synchronization
can be achieved in a broad class of oscillators with little constraint on their
intrinsic property. On the other hand, the leaky integrate-and-fire neuron
oscillators do not belong to this class, generating intermittent phase slips
according to a power low distribution of their intervals.Comment: 10 pages, 3 figure
Respon Tanaman Kacang-Kacangan yang Bersifat Determinate dan Indeterminate pada Berbagai Kondisi Ketersediaan Air
Growth and yield of soybean and blackgram, having determinate and indeterminate in flowering respectively, were compared under three water regimes. Under well-watered conditions, blackgram continuously produces flowers where under rainfed + irrigation and rainfed condition, two periods of flowering can be distinguished. While only one period of flowering was observed in soybean. The second flush of flowering of blackgram in rainfed and rainfed + irrigation areas occurred during high rain fall. Partial irrigation as much as 80 mm toward the end of pod filling in soybean did not give benefit to soybean, but irrigation stimulate flowering in blackgram and increase yield up to 25%. Thus indeterminate behavior might give higher yield under rainfed condition due to its flexibility of flowering.  Key words: Determinate, Indeterminate, Flowering, Water stres
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