Influence of Elevated CO2 and Phosphorus Nutrition on the Growth and Yield of a Short-Duration Rice (Oryza sativa L. Cv. Jarrah)

The growth and development of a short-duration rice cultivar (Oryza sativa L. cv. Jarrah), grown in flooded soil with a range of phosphorus (P) levels and exposed to atmospheric CO2 concentrations of either 350 or 700 μL L-1 was followed for 146 days after planting (DAP). Development (estimated by rate of tiller production and time to flowering) was faster with higher soil P levels and CO2 enrichment, the effect being more pronounced with CO2 enrichment. During the early vegetative phase (up to 35 DAP), when rates of tiller production were low, shoot growth and rates of leaf expansion were faster at elevated CO2 concentrations and high soil P levels. Rates of tiller production were greater with these treatments during the 35-56 DAP period, when tillering was at a maximum. Shoot elongation was reduced at elevated CO2 levels and at high soil P levels during this period. By 146 DAP leaf weight was greater at high P levels, but CO2 enrichment accelerated tiller production to such an extent that final leaf weight was lower at high CO2, probably because there were fewer, and smaller, leaves on each tiller. Despite this, grain yield was increased by up to 58% by CO2 enrichment, with increases occurring even at low soil P levels. This was due mainly to an increase in grain number per panicle, although panicle number also increased. Higher soil P levels also increased grain number and yield. The P concentration in the foliage was unaffected by the CO2 treatments and the concentration required to produce maximum yield was 0.18% (dry wt basis) at both CO2 levels. Greater starch accumulation in the stems of high-CO2-grown plants may have accounted for the higher number of grains in each panicle.

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Nitrogen requirements for maximum growth and photosynthesis of rice, Oryza sativa L. cv. Jarrah grown at 36 And 70 Pa CO2

Functional Plant Biology ◽

10.1071/pp99067 ◽

1999 ◽

Vol 26 (8) ◽

pp. 759 ◽

Cited By ~ 18

Author(s):

Silvestre K. Aben ◽

Saman P. Seneweera ◽

Oula Ghannoum ◽

Jann P. Conroy

Keyword(s):

Oryza Sativa ◽

Elevated Co2 ◽

Oryza Sativa L ◽

Morphological Changes ◽

Critical Concentration ◽

Maximum Growth ◽

Soluble Carbohydrate ◽

High Co2 ◽

Photosynthetic Rates ◽

Co2 Partial Pressure

The hypothesis that growth of rice (Oryza sativa L. cv. Jarrah) at elevated atmospheric CO2 partial pressure alters leaf nitrogen (N) concentrations required to support maximum dry mass production and photosynthetic rates during the period of rapid tiller initiation was tested by growing plants for 30 days in unstirred sand/hydroponic culture with N concentrations of 5, 20, 40, 60 and 100 mg N L–1. Maximum growth and photosynthetic potential was greater at 70 than 36 Pa CO2 at all N concentrations in the solution. Elevated CO2 reduced leaf N concentrations required to support 90% of maximum growth and photosynthetic rates (critical concentration) from 40 to 27 g kg–1 for growth and from 45 to 30 g kg–1 for photosynthesis. Morphological changes at elevated CO2 included increased tiller numbers and reduced leaf area ratio. The latter could be explained by lower plant N concentrations which occurred at high CO2 at each N concentration in the solution, primarily due to lower leaf blade and root N concentrations. Changes in tiller numbers at high CO2 were unrelated to leaf or plant N but were strongly correlated with leaf soluble carbohydrate concentrations. We conclude that elevated CO2 alters the nutritional physiology of rice during the rapid tillering phase in a way that increases the efficiency of N utilisation for growth and photosynthesis.

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Physiological resilience of pink salmon to naturally occurring ocean acidification

Conservation Physiology ◽

10.1093/conphys/coaa059 ◽

2020 ◽

Vol 8 (1) ◽

Author(s):

Andrea Y Frommel ◽

Justin Carless ◽

Brian P V Hunt ◽

Colin J Brauner

Keyword(s):

British Columbia ◽

Elevated Co2 ◽

Condition Factor ◽

Pacific Salmon ◽

Pink Salmon ◽

Hypoxia Tolerance ◽

High Co2 ◽

The North ◽

Naturally Occurring ◽

Co2 Levels

Abstract Pacific salmon stocks are in decline with climate change named as a contributing factor. The North Pacific coast of British Columbia is characterized by strong temporal and spatial heterogeneity in ocean conditions with upwelling events elevating CO2 levels up to 10-fold those of pre-industrial global averages. Early life stages of pink salmon have been shown to be affected by these CO2 levels, and juveniles naturally migrate through regions of high CO2 during the energetically costly phase of smoltification. To investigate the physiological response of out-migrating wild juvenile pink salmon to these naturally occurring elevated CO2 levels, we captured fish in Georgia Strait, British Columbia and transported them to a marine lab (Hakai Institute, Quadra Island) where fish were exposed to one of three CO2 levels (850, 1500 and 2000 μatm CO2) for 2 weeks. At ½, 1 and 2 weeks of exposure, we measured their weight and length to calculate condition factor (Fulton’s K), as well as haematocrit and plasma [Cl−]. At each of these times, two additional stressors were imposed (hypoxia and temperature) to provide further insight into their physiological condition. Juvenile pink salmon were largely robust to elevated CO2 concentrations up to 2000 μatm CO2, with no mortality or change in condition factor over the 2-week exposure duration. After 1 week of exposure, temperature and hypoxia tolerance were significantly reduced in high CO2, an effect that did not persist to 2 weeks of exposure. Haematocrit was increased by 20% after 2 weeks in the CO2 treatments relative to the initial measurements, while plasma [Cl−] was not significantly different. Taken together, these data indicate that juvenile pink salmon are quite resilient to naturally occurring high CO2 levels during their ocean outmigration.

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Daya Gabung Beberapa Varietas Padi (Oryza sativa L.) pada Persilangan Dialel Menggunakan Metode Griffing II

Jurnal Sains Teknologi & Lingkungan ◽

10.29303/jstl.v0i0.257 ◽

2021 ◽

pp. 84-93

Author(s):

Anak Agung Ketut Sudharmawan ◽

Baiq Erna Listiana ◽

Sofi Rianti

Keyword(s):

Oryza Sativa ◽

Plant Height ◽

Power Analysis ◽

Oryza Sativa L ◽

Panicle Length ◽

Grain Number ◽

Significant Difference ◽

Diallel Crossing ◽

High Yielding Varieties ◽

Materials Used

Diallel crossing is a method that is widely used to determine the ability to combine each individual so that it can identify the potential elders to be used in crossbreeding programs to assemble high yielding varieties. This experiment aims to determine the combining power of dialelic crosses of several varieties of rice using the Griffing II method, carried out in the experimental field of the Faculty of Agriculture, Mataram University in Nyiur Lembang Village, Narmada District, West Lombok Regency, from February to July 2019. This experiment uses the method experiments carried out in the field. The materials used in this experiment were four parents, namely IPB 3S variety, Situ Patenggang variety, Inpari 32 and G11 strain and the phenotype of the cross between the four parents. The experimental results showed that the effects of general affinity and special affinity for all observed characters (plant height, number of productive tillers, number of non-productive tillers, panicle length, number of filled grain, number of empty grain and weight of 100 grains) were significantly different, except on the effect of general affinity for the number of non-productive tillers showed no significant difference. The results of the combined power analysis of the four elders were positive, so it can be said that the four elders would get good results when crossed with a number of other genotypes.

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