The development of barley grain: comparisons between cultivars for growth rate and α-amylase activity

1976 ◽  
Vol 86 (3) ◽  
pp. 603-608 ◽  
Author(s):  
T. J. Riggs ◽  
P. G. Gothard

SummaryGrains from ears of known anthesis time in seven spring barley cultivars were measured for dry weight and α-amylase activity at regular intervals during grain maturation. During the period 10–31 days after anthesis, dry weight increase of the grain was found to be substantially linear in all the cultivars. Comparisons between linear slopes fitted for this phase of growth were found to provide an objective means of comparing grain growth rates in different cultivars.α-Amylase activity per grain reached a peak in all except one cultivar at between 10 and 16 days after anthesis but declined rapidly during the linear phase of grain growth. α-Amylase activity per gram grain dry weight decreased exponentially during this period and transformation of the data to logarithms allowed a substantially linear fit to be made. Slopes for each of the cultivars were compared.Differences were found between cultivars in grain growth rates, total α-amylase activity and rates of fall of α-amylase activity per gram for the period 10–31 days after anthesis. No relationship could be found between grain growth rate and either the absolute level of α-amylase activity achieved in the grain or the rate of fall in activity during development.

1983 ◽  
Vol 100 (2) ◽  
pp. 383-391 ◽  
Author(s):  
W. R. Scott ◽  
Margaret Appleyard ◽  
Gwynneth Fellowes ◽  
E. J. M. Kirby

SUMMARYGrain growth and final weight per grain were measured in 12 genotypes of spring barley, the parents and progeny of two six-row × two-row crosses. Weight of carpels or grains from node 10 on the main shoot ear was measured from shortly after meiosis until grains were at maximum dry weight. Similar measurements were made at representative node positions along the ear of Proctor and of Midas spring barley cultivars.From about 10 days after anthesis grains grew at a constant rate for about 3 weeks. Amongst genotypes growth rate of the median grain ranged from 1·4 to 2'2 mg/day and there was a very highly significant positive correlation between growth rate and final grain weight. A similar relationship was found among grain positions on the ear. For about 10 days after anthesis growth was exponential and although relative growth rate did not differ between genotypes or grain positions there was a highly significant difference between caryopsis weights during this phase. There were significant correlations between final grain weight and carpel weight at anthesis and between final grain weight and husk weight at anthesis. In the period between meiosis and anthesis growth was exponential and the relative growth rate did not differ between genotypes or node positions on the ear. There were significant differences between carpel weights during this phase. Carpel weight at anthesis and carpel linear dimensions at meiosis were correlated.These data suggest that the initial size of carpel is an important factor in determining growth rate and potential grain weight. Potential grain size in barley may be determined by physical limitations imposed by the lemma and palea or may be causally related to the size of the carpel. The relative size of the carpel is determined by the time of meiosis and potential size may also be affected by pre-anthesis conditions.


1974 ◽  
Vol 83 (2) ◽  
pp. 213-221 ◽  
Author(s):  
P. R. Goldsworthy ◽  
M. Colegrove

SUMMARYThe growth and yield of five highland varieties of tropical maize were studied. Grain yields were between 4·7 and 8·8 t/ha. Crop growth rates (C) increased to a maximum of between 25 and 35 g/m2/day at silking and then declined. Grain growth rates (maximum 21 g/m2/day) exceeded current C during most of the grain-filling period.After silking, when C exceeded grain growth rate, dry matter accumulated in the stem and husk, resulting in an increase of from 200 to 600 g/m2. Later, as grain growth rate increased and exceeded current C, some of this accumulated material was incorporated into the grain, and stem weight decreased. A comparison of the dry weight changes after flowering in these varieties with those reported for a hybrid that yielded 12 t grain/ha indicates that the smaller yield of the Mexican varieties was associated with smaller grain growth rates and the incorporation into the grain of a smaller fraction of the dry weight produced after flowering. These results suggest that the capacity of the grain ‘sink’ to utilize assimilates limited yields in the tropical varieties.


1970 ◽  
Vol 15 ◽  
pp. 69-75
Author(s):  
MSI Mollah ◽  
NK Paul

An experiment was conducted in the experimental field of Rajshahi University Campus (AEZ-11) to study the influence of soil moisture and NPK fertilizers on grain growth of four varieties of barley (Hordeum velgare L.). Spikelet number (SN), spike dry weight (SDW), grain number (GN), grain dry weight (GDW), spike relative growth rate (spike RGR) and grain relative growth rate (grain RGR) were observed highest in the highest level of irrigation (40 mm). The highest amount of fertilizer (120N 75P 45K) produced the highest SN, SDW, GN, GDW, spike RGR and grain RGR. BHL-3 produced the highest SN, BARI Barley -2 produced the highest spike RGR, BARI Barley -1 produced the highest grain RGR and BL-1 produced the highest SDW, GN, and GDW. Key words: Irrigation, soil moisture, fertilizers, barley, grain growth.   doi: 10.3329/jbs.v15i0.2205 J. bio-sci. 15: 69-75, 2007


1971 ◽  
Vol 51 (6) ◽  
pp. 469-477 ◽  
Author(s):  
D. E. LaBERGE ◽  
A. W. MacGREGOR ◽  
W. O. S. MEREDITH

The percentage of dry matter, kernel weight, α-amylase activity and β-amylase activity, were determined at several stages of kernel development, from anthesis to harvest, in seven cultivars of Canadian barley. These included 6-row barleys (Conquest, Bonanza, and Keystone), 2-row barleys (Betzes and Centennial), and two 6-rowed selections from crosses between 2-row and 6-row barleys. The patterns for development of β-amylase enzymes were similar in all cultivars, and these activities were low initially, followed by a period of increasing activities commencing about 10 days after anthesis and reaching maximum values 20 days later; they then remained constant until the kernels were harvested. α-Amylase activity increased in all cultivars immediately after anthesis and then decreased to low levels after 10 days of kernel development. The α-amylase activities of Conquest, Bonanza, and Betzes increased again to quite high levels after maturity and just prior to delayed harvesting, owing to unfavorable weather that caused sprouting in these cultivars.


2015 ◽  
Vol 40 (3) ◽  
pp. 423-430 ◽  
Author(s):  
A. Rejowski

The effect of GA<sub>3</sub> on ribonuclease activity in the embryos and endosperm of barley seeds was investigated during dormancy and after its end. Incubation of dormancy grain with GA<sub>3</sub> stimulated its germination, increased the dry weight of the embryos and their protein content. Ribonuclease activity in seeds treated with GA<sub>3</sub> was considerably enhanced. The increase was more rapid and intensive in the embryos than in the endosperm. The action of GA<sub>3</sub> was most effective, particularly as regards the endosperm, on grain which had already passed through the stage of dormancy and had reached physiological maturity. This is evidence that the internal factor regulating the process of dormancy exerts a stronger influence on the activity of ribonuclease than does exogenic giberrellic acid.


1977 ◽  
Vol 4 (5) ◽  
pp. 785 ◽  
Author(s):  
I Sofield ◽  
LT Evans ◽  
MG Cook ◽  
IF Wardlaw

Controlled-environment conditions were used to examine the effects of cultivar and of temperature and illuminance after anthesis on grain setting and on the duration and rate of grain growth. After an initial lag period, which did not differ greatly between cultivars, grain dry weight increased linearly under most conditions until final grain weight was approached. Growth rate per grain depended on floret position within the ear, varied between cultivars (those with larger grains at maturity having a faster rate), and increased with rise in temperature. With cultivars in which grain number per ear was markedly affected by illuminance, light had relatively little effect on growth rate per grain. With those in which grain number was less affected by illuminance, growth rate per grain was highly responsive to it, especially in the more distal florets. In both cases there was a close relation between leaf photosynthetic rate as influenced by illuminance, the rate of grain growth per ear, and final grain yield per ear. The duration of linear grain growth, on the other hand, was scarcely influenced by illuminance, but was greatly reduced as temperature rose, with pronounced effects on grain yield per ear. Cultivars differed to some extent in their duration of linear growth, but these differences accounted for less of the difference in final weight per grain than did those in rate of grain growth. Under most conditions the cessation of grain growth did not appear to be due to lack of assimilates.


1979 ◽  
Vol 36 (12) ◽  
pp. 1497-1502 ◽  
Author(s):  
L. J. Buckley

The protein, DNA, and RNA content of larvae maintained at 1.0 plankter/mL increased at the rates of 9.3, 9.9, and 9.8% per day, respectively, for the 5 wk after hatching. Protein reserves of larvae held at 0 or 0.2 plankters/mL were depleted by 45 and 35%, respectively, prior to death 12–13 d after hatching. Starved larvae had similar protein concentrations (percent of dry weight), lower RNA concentrations, and higher DNA concentrations than fed larvae. Larvae held at higher plankton densities had higher RNA–DNA ratios and faster growth rates than larvae held at lower plankton densities. The RNA–DNA ratio was significantly correlated (P < 0.01) with the protein growth rate. The RNA–DNA ratio appears to be a useful index of nutritional status in larval Atlantic cod (Gadus morhua) and may be useful for determining if cod larvae were in a period of rapid or slow growth at the time of capture. Key words: RNA–DNA ratio, starvation, protein, nucleic acids, growth, larval fish, Atlantic cod


1955 ◽  
Vol 33 (5) ◽  
pp. 416-428 ◽  
Author(s):  
D. E. Etheridge

Cultures of Fames annosus originating in Europe could not be distinguished from those originating in North America either by colony appearance, growth rate, pH optimum, or cellulolytic activity. Three growth rate types on 2.5% malt agar were recognized and these are ascribed to individual variation rather than to host or geographical influences. Successive subculturing produced variants that fell into three growth classes. Half of the isolates displayed spontaneous, but reversible, changes in growth rate and colony appearance during subculturing and this is discussed from the standpoint of genetical and environmental influences. Cultures displaying different morphological characteristics and linear-growth rates differed little metabolically; each had a similar pH optimum ranging from 4.6 to 5.5, and each proved capable of altering the initial acidity of the medium to a reaction which was more suitable for growth. Two cultures were characterized by double pH optima at 4.6 and 5.5. Cultures having different linear-growth rates produced about the same dry-weight of mycelium on a cellulose substrate in a semisynthetic nutrient solution. On the basis of a statistical analysis of cellulose utilization by representative isolates it was impossible to distinguish between North American and European cultures.


1996 ◽  
Vol 42 (141) ◽  
pp. 255-260 ◽  
Author(s):  
R. B Alley ◽  
G. A. Woods

AbstractIntercept analysis of approximately bi-yearly vertical thin sections from the upper part of the GISP2 ice Core, central Greenland, shows that grain-size ranges increase with increasing age. This demonstrates that something in the ice affects grain-growth rates, and that grain-size cannot be used directly in paleothermometry as has been proposed. Correlation of grain-growth rates to chemical and isotopic data indicates slower growth in ice with higher impurity concentrations, and especially slow growth in “forest-fire” layers containing abundant ammonium; however, the impurity/grain-growth relations are quite noisy. Little correlation is found between growth rate and isotopic composition of ice.


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