scholarly journals Discovery of a few photosynthesis models through red light absorbance-transmittance of the e1 leaf sectors of newly bred hybrids of maize (Zea mays L.)

Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

Background: Pipeline hybrids of maize must be evaluated very intensively and from several perspectives in order to extract reliability of success of the hybrids in farmers’ field before their release as cultivars and to extract some useful physiology preferably photosynthesis, source-sink relationship and tolerance of green LS (leaf sectors) under biotic and abiotic stresses as scientists’ bonus. For it, five pipeline single cross hybrids of yellow maize have been examined from the standpoint of photosynthetic potentiality of central leaf and nutrient mobilization from it to ear for grain fill. Materials and methods: Just above ear (e1) leaf have been minutely examined through ratio of absorbance to transmittance of red light of 650 nm (RAT) measure, chl and N concentration (conc). From correlation coefficients (r) computed between frequency of LS of varying RAT SPAD (Soil Plant Analysis and Development) measures, chl and N conc; few photosynthetic models have been proposed to explain leaf physiologies and its effects on grain yields. Results and discussions: Through analysis of frequency distribution of RAT measures and r between frequency of LS of varying RAT SPAD measure and grain yield, RATA Makai model has been proposed to explain for a variety of efficiency of antennae to harvest light energy especially red photons and transfer the energy to reaction centers (RCs). It includes two types of classification of antenna. Next is diversity model to explain existence of four types leaf sector such as narrow, medium, wide diversity with least bad LS in central leaf of the maize based on photosynthetic efficiency of variety of the photosynthetic e1 LS that they are differentially contributing to grain yields. This sort of LS diversity study helps classify character of LS based on RAT and or chl and N conc. A few more models proposed in it are NARC (Nitrogen Concentration in Antenna and Reaction Centers) and PAY (Protein Amounts and its effects on Yield) based on r between grain yield and leaf N and protein amounts. In addition; strong positive r has been found between grain yields and the frequencies of the LS of 46-52 RAT SPAD; 46-56 µg cm-2 of chl conc and 2-2.3% N of dry weight; This way, we proposed about threshold and upper limit of the RAT SPAD, chl and N conc in maize leaves. It implies that cells in these ranges are genotype based multiplicative and physiologically active and competent to make their identity in the e1 leaf of the hybrids for GY contribution. In addition, next model of ‘green car’ with the four kinds of proportion of green and carotenoid (car) conc: high green-high car to produce high grain yield and remaining proportion such as high green-low car, low green-high car and low green-low car on maize leaves to cause low grain yield has been proposed. Concept of high green-low car conc in maize leaf gives extended model of no car-no food.

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

Background: Pipeline hybrids of maize must be evaluated very intensively and from several perspectives in order to extract reliability of success of the hybrids in farmers‟ field before their release as cultivars and to extract some useful physiology preferably photosynthesis, source-sink relationship and tolerance of green LS (leaf sectors) under biotic and abiotic stresses as scientists‟ bonus. For it, five pipeline single cross hybrids of yellow maize have been examined from the standpoint of photosynthetic potentiality of central leaf and nutrient mobilization from it to ear for grain fill. Materials and methods: Just above ear (e1) leaf have been minutely examined through ratio of absorbance to transmittance of red light of 650 nm (RAT) measure, chl and N concentration (conc). From correlation coefficients (r) computed between frequency of LS of varying RAT SPAD (Soil Plant Analysis and Development) measures, chl and N conc; a few photosynthesis models have been proposed to explain leaf physiologies and its effects on grain yields. Results and discussions: Through analysis of frequency distribution of RAT measures and r between frequency of LS of varying RAT SPAD measure and grain yield, RATA Makai model has been proposed to explain for a variety of efficiency of antennae to harvest light energy especially red photons and transfer the energy to reaction centers (RCs). Functional, semi-functional and least functional antenna have been classified. Next is diversity model to explain existence two types of diversity of leaf sector such as narrow and wide diversity with least bad LS in central leaf of the maize based on photosynthetic efficiency of a variety of the photosynthetic e1 LS that they are differentially contributing to grain yields. This sort of LS diversity study helps classify character of LS based on RAT and or chl and N conc. A few more models proposed in it are NARC (Nitrogen Concentration in Antenna and Reaction Centers) and PAY (Protein Amounts and its effects on Yield) based on r between grain yield and leaf N and protein amounts. In addition; strong positive r has been found between grain yields and the frequencies of the LS of 46-52 RAT SPAD; 46-56 μg cm-2 of chl conc and 2-2.3% N of dry weight; This way, we proposed about threshold and upper limit of the RAT SPAD, chl and N conc in maize leaves. It implies that cells in these ranges are genotype based multiplicative and physiologically active and competent to make their identity in the e1 leaf of the hybrids for GY contribution. Furthermore, next model of „green car‟ with the four kinds of proportion of green and carotenoid (car) conc: high green-high car to produce high grain yield and remaining proportion such as high green-low car, low green-high car and low green-low car on maize leaves to cause low grain yield has been proposed. Concept of high green-low car conc in maize leaf gives extended model of no car-no food.


2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

Background: Pipeline hybrids of maize must be evaluated very intensively and from several perspectives in order to extract reliability of success of the hybrids in farmers’ field before their release as cultivars and to extract some useful physiology preferably photosynthesis and tolerance of green LS (leaf sectors) under biotic and abiotic stresses as scientists’ bonus. For it, five pipeline single cross hybrids of yellow maize have been examined from the standpoint of photosynthetic potentiality of central leaf and nutrient mobilization from it to ear for grain fill. Materials and methods: Just above ear (e1) leaf have been minutely examined through ratio of absorbance to transmittance of red light of 650 nm (RAT) measure, chl and N concentration (conc). From correlation coefficients (r) computed between grain yield (GY) and frequency of LS of varying RAT SPAD (Soil Plant Analysis and Development) measures, chl and N conc; a few photosynthesis models have been proposed to explain leaf physiologies and its effects on GY. Results and discussions: Through analysis of frequency distribution of RAT measures and r between GY and frequency of LS of varying RAT (SPAD) measure, RATA Makai model has been proposed to explain for a variety of efficiency of antennae to harvest light energy especially red photons and transfer the energy to reaction centers (RCs). Antenna has been classified into functional, semi-functional and least functional based on their contribution on GY. Next is diversity model to explain existence of two types of diversity of leaf sector such as narrow and wide diversity on the central maize leaf based on r between GY and frequency of LS of varying RAT. This sort of LS diversity study helps classify nature of LS based on RAT and or chl and N conc. A few more models proposed in it are NARC (Nitrogen Concentration in Antenna and Reaction Centers) and PAY (Protein Amounts and its effects on Yield) based on r between GY and leaf N and protein amounts. In addition; strong positive r has been found between GY and the frequencies of the LS of 46-52 RAT SPAD; 46-56 μg cm-2 of chl conc and 2-2.3% N of dry weight; This way, we proposed about threshold and upper limit of the RAT SPAD, chl and N conc in maize leaves. It implies that cells in the RAT SPAD range 46-52 are genotype based multiplicative, physiologically active and competent to make their identity in the e1 leaf of the hybrids for GY contribution. Furthermore, next model of “green car” has been proposed for four kinds of proportion of green and carotenoid (car) conc: high green-high car, high green-low car, low green-high car and low green-low car on maize leaves and their effects on grain yield and dry matter production. We can extract a model of no car-no food from the existence of effect phenomena of high green-low car conc on the low dry matter and GYs in maize.


2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

Background: Pipeline hybrids of maize must be evaluated very intensively and from several perspectives in order to extract reliability of success of the hybrids in farmers’ field before their release as cultivars and to extract some useful physiology preferably photosynthesis and tolerance of green LS (leaf sectors) under biotic and abiotic stresses as scientists’ bonus. For it, five pipeline single cross hybrids of yellow maize have been examined from the standpoint of photosynthetic potentiality of central leaf and nutrient mobilization from it to ear for grain fill. Materials and methods: Just above ear (e1) leaf have been minutely examined through ratio of absorbance to transmittance of red light of 650 nm (RAT) measure, chl and N concentration (conc). From correlation coefficients (r) computed between grain yield (GY) and frequency of LS of varying RAT SPAD (Soil Plant Analysis and Development) measures, chl and N conc; a few photosynthesis models have been proposed to explain leaf physiologies and its effects on GY. Results and discussions: Through analysis of frequency distribution of RAT measures and r between GY and frequency of LS of varying RAT (SPAD) measure, RATA Makai model has been proposed to explain for a variety of efficiency of antennae to harvest light energy especially red photons and transfer the energy to reaction centers (RCs). Antenna has been classified into functional, semi-functional and least functional based on their contribution on GY. Next is diversity model to explain existence of two types of diversity of leaf sector such as narrow and wide diversity on the central maize leaf based on r between GY and frequency of LS of varying RAT. This sort of LS diversity study helps classify nature of LS based on RAT and or chl and N conc. A few more models proposed in it are NARC (Nitrogen Concentration in Antenna and Reaction Centers) and PAY (Protein Amounts and its effects on Yield) based on r between GY and leaf N and protein amounts. In addition; strong positive r has been found between GY and the frequencies of the LS of 46-52 RAT SPAD; 46-56 μg cm-2 of chl conc and 2-2.3% N of dry weight; This way, we proposed about threshold and upper limit of the RAT SPAD, chl and N conc in maize leaves. It implies that cells in the RAT SPAD range 46-52 are genotype based multiplicative, physiologically active and competent to make their identity in the e1 leaf of the hybrids for GY contribution. Furthermore, next model of “green car” has been proposed for four kinds of proportion of green and carotenoid (car) conc: high green-high car, high green-low car, low green-high car and low green-low car on maize leaves and their effects on grain yield and dry matter production. We can extract a model of no car-no food from the existence of effect phenomena of high green-low car conc on the low dry matter and GYs in maize.


2012 ◽  
Vol 4 (11) ◽  
Author(s):  
Ali Hafeez Malik ◽  
Allan Andersson ◽  
Ramune Kuktaite ◽  
Muhammad Yaqub Mujahid ◽  
Bismillah Khan ◽  
...  

1982 ◽  
Vol 98 (2) ◽  
pp. 347-355 ◽  
Author(s):  
R. W. Daniels ◽  
M. B. Alcock ◽  
D. H. Scarisbrick

SUMMARYPre-anthesis stem reserve contribution to grain yield was assessed in two spring barley cultivars of contrasting height. It was greatest in the taller, but final grain yields were similar. Partitioning of total reserve capacity to various plant parts showed that the leaf and sheath below the peduncle were most important, followed by stem internodes which had increasing reserve capacity up to internode 4.It is suggested that stem reserves are valuable for yields commonly achieved in U.K. commercial practice.High grain yields were associated with large positive increases in stem dry weight after anthesis. This would indicate that the source capacity to boost yield is more than proportional to that required to fill the grain alone.


2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

National maize productivity is very low in Nepal. To increase its productivity, hybrid maize breeding and their cultivation are indispensible. For it, fifteen newly bred single cross hybrids of yellow maize were examined to select superior high GYHs (grain yielding hybrids) from the standpoint grain yielding potentiality. In addition, dynamics of chl, N conc and red light absorbance-transmittance (RAT) have also examined from the standpoint of chl, N conc and RAT measure and their effects on grain yield (GY). For it, a trial of RCBD experiment was conducted in open field in winter in subtropical region in Nepal. Seeds were sown on October 3, 2012 plot in two row plot area of 1.4 x 3.0 m2. After anthesis, observations of chl and N conc implying RAT (red light absorbance-transmittance) SPAD (Soil Plant Analysis and Development) measures were taken from the topmost ear (e0 or E0) and third (e3 or E3) leaf above the e0 leaf in ten days interval during entire grain filling (GF). SPAD measures were transformed to total chl and N conc. E0 leaf has been found more grain yield determining than e3 leaf and terminal GF has been found more determining than early GF from the standpoint of correlation coefficients (r ) of GYs with chl, N conc and SPAD measure. From pooled variance analysis; SPAD and chl conc were not significant different in the two leaves and among the hybrids (Hybrids x Leaves x Ages). But, the SPAD and chl conc were significant different among the two leaves and ages (Leaves x Ages) irrespective of the hybrids. Different to the SPAD and chl conc, N conc was significant different in the leaves among the hybrids with respect to ages of the plants among the fifteen hybrids (Hybrids x Leaves x Ages). Thirteen top high GYHs 8, 12, 11, 13, 5, 6, 10, 1, 7, 14, 2, 9 and 15 were non-significant different from the standpoint of GY. The SPAD measures were in the non-significant range of 51-55 in e0 leaf in the duration from 95 to 125 d among the fifteen hybrids (FHs). Among the top four high GYHs 8, 12, 11 and 13; hybrid 11 lost chl and N from e0 leaf significantly on 135th d relative to the most of the hybrids. It means that the hybrid 11 could efficiently degrade N containing soluble protein and chl even on e0 leaf relatively. Top listed five high GYHs 8, 12, 11, 5 and 6 (except 13) constantly maintained chl and N conc implying SPAD on the e0 leaf up to the 135th d. In addition, it implies that these five hybrids sent newly up-taken N to kernels without degradation of the proteins and chl from the e0 leaf till the age of 135 d. High GYH 8 had degraded soluble proteins and enzymes and chl conc on e3 leaf and mobilized the degraded N to the kernels more efficiently from the e3 leaf. It is not necessary that maize hybrids must constantly maintain soluble proteins and chl conc during most of early to mid GF for high GY. Instead, diagnostic decline of the soluble protein and chl conc during early to mid GF also accelerate GF phenomena.


2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala

National maize productivity is very low in Nepal. To increase its productivity, hybrid maize breeding and their cultivation are indispensible. For it, fifteen newly bred single cross hybrids of yellow maize were examined to select superior high GYHs (grain yielding hybrids) from the standpoint grain yielding potentiality. In addition, dynamics of chl, N conc and red light absorbance-transmittance (RAT) have also examined from the standpoint of chl, N conc and RAT measure and their effects on grain yield (GY). For it, a trial of RCBD experiment was conducted in open field in winter in subtropical region in Nepal. Seeds were sown on October 3, 2012 plot in two row plot area of 1.4 x 3.0 m2. After anthesis, observations of chl and N conc implying RAT (red light absorbance-transmittance) SPAD (Soil Plant Analysis and Development) measures were taken from the topmost ear (e0 or E0) and third (e3 or E3) leaf above the e0 leaf in ten days interval during entire grain filling (GF). SPAD measures were transformed to total chl and N conc. E0 leaf has been found more grain yield determining than e3 leaf and terminal GF has been found more determining than early GF from the standpoint of correlation coefficients (r ) of GYs with chl, N conc and SPAD measure. From pooled variance analysis; SPAD and chl conc were not significant different in the two leaves and among the hybrids (Hybrids x Leaves x Ages). But, the SPAD and chl conc were significant different among the two leaves and ages (Leaves x Ages) irrespective of the hybrids. Different to the SPAD and chl conc, N conc was significant different in the leaves among the hybrids with respect to ages of the plants among the fifteen hybrids (Hybrids x Leaves x Ages). Thirteen top high GYHs 8, 12, 11, 13, 5, 6, 10, 1, 7, 14, 2, 9 and 15 were non-significant different from the standpoint of GY. The SPAD measures were in the non-significant range of 51-55 in e0 leaf in the duration from 95 to 125 d among the fifteen hybrids (FHs). Among the top four high GYHs 8, 12, 11 and 13; hybrid 11 lost chl and N from e0 leaf significantly on 135th d relative to the most of the hybrids. It means that the hybrid 11 could efficiently degrade N containing soluble protein and chl even on e0 leaf relatively. Top listed five high GYHs 8, 12, 11, 5 and 6 (except 13) constantly maintained chl and N conc implying SPAD on the e0 leaf up to the 135th d. In addition, it implies that these five hybrids sent newly up-taken N to kernels without degradation of the proteins and chl from the e0 leaf till the age of 135 d. High GYH 8 had degraded soluble proteins and enzymes and chl conc on e3 leaf and mobilized the degraded N to the kernels more efficiently from the e3 leaf. It is not necessary that maize hybrids must constantly maintain soluble proteins and chl conc during most of early to mid GF for high GY. Instead, diagnostic decline of the soluble protein and chl conc during early to mid GF also accelerate GF phenomena.


2008 ◽  
Vol 53 (No. 9) ◽  
pp. 395-402 ◽  
Author(s):  
J. Potarzycki ◽  
W. Grzebisz

Malt barley production requires a technology increasing nitrogen use efficiency, because of a high sensitivity of barley total grain yield and quality parameters to external growth factors. In the conducted study an effect of two P fertilizers on the background of N application on total and technological grain yields were studied. The highest total grain yield was harvested on plots fertilized with 60 kg N/ha, irrespective of the P fertilizer type. However, the technological grain yield showed a high year-to-year variability; the highest was recorded in 2001 on the plot fertilized with 60 kg N/ha and the P-PAPR fertilizer. The N and S concentrations and N:S ratios in immature grains at harvest were used to evaluate both yield types. Nitrogen concentration in the final total yield allowed making yields prognosis with the highest probability. The maximum yields of technological malt barley were attainable provided that total S concentration in immature grains at harvest was above 0.23% and the N:S ratio was narrower than 8.0.


1967 ◽  
Vol 47 (4) ◽  
pp. 359-365 ◽  
Author(s):  
H. D. Voldeng ◽  
G. M. Simpson

Shading treatments with a high- and a low-yielding line of wheat indicated that the ear and flag leaf contributed the major portion of grain dry weight. Correlation coefficients calculated between flag-leaf area and grain yield, and ear area and grain yield, from tillers within seven lines of wheat ranged from + 0.54 to + 0.90. The combination of a large flag leaf plus a large ear area showed promise as an index for selecting higher yielding individuals from a mixture of genotypes.


1980 ◽  
Vol 60 (1) ◽  
pp. 61-68 ◽  
Author(s):  
J. M. DESCHENES ◽  
C. A. ST-PIERRE

On a St-André sandy loam and on a Kamouraska clay, the effect of soil temperature on oats (Avena sativa L.) was measured in the greenhouse using a system described by Deschênes et al. in 1974 and in the field, using two dates of seeding. The effect of weeds was measured by using un weeded and hand-weeded treatments. In the greenhouse, cool soil temperatures have delayed maturity and decreased straw and grain yields as well as total phytomass of oats on the two soil types. The dry weight of weeds in un weeded pots increased slightly. The effect of hand-weeding on oats was especially noticeable on the St-André sandy loam where three times as many weeds were observed. The straw yield and the total phytomass of oats were higher in the field experiment following an early seeding of oats on both soil types. On the other hand, grain yield was lower on plots seeded early and located on St-André sandy loam while the opposite was true on Kamouraska clay. The dry weight of weeds was lower on unweeded plots seeded early. The weeds reduced straw and grain yields on the St-André sandy loam but had no effect on Kamouraska clay because of the low weed infestation on the latter. The greenhouse and field experiments suggest that soil temperature is not the main factor in explaining the increase in grain yield observed with early-seeded cereals.


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