scholarly journals Dynamics of chlorophyll and N concentration on e0 and e3 leaves of maize hybrids in winter in subtropical region

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Soluble Protein ◽  
Red Light ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Soluble Proteins ◽  
Subtropical Region ◽  
Maize Breeding ◽  
Maize Hybrids ◽  
Light Absorbance

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.

scholarly journals Dynamics of chlorophyll and N concentration on e0 and e3 leaves of maize hybrids in winter in subtropical region

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Soluble Protein ◽  
Red Light ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Soluble Proteins ◽  
Subtropical Region ◽  
Maize Breeding ◽  
Maize Hybrids ◽  
Light Absorbance

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.

scholarly journals Dynamics of chlorophyll and N concentration on e0 and e3 leaves of maize hybrids in winter in subtropical region

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Soluble Protein ◽  
Red Light ◽  
Grain Filling ◽  
Soluble Proteins ◽  
Subtropical Region ◽  
Maize Hybrids ◽  
N Concentration ◽  
Single Cross ◽  
Grain Filling Duration

National maize productivity is very low in Nepal. Increase of the productivity is only possible through growing high grain yielding single cross hybrid maize cultivar. So, development and evaluation of maize hybrids are principal steps to select high grain yielding and superior hybrid for cultivar. For it, fifteen newly bred single cross hybrids of yellow maize were examined from the standpoint of chlorophyll (chl) dynamics and their effects on grain yield. 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, chl and N concentration (conc) implying RAT (red light absorbance-transmittance) SPAD measure were taken from the topmost ear (e0) and third (e3) leaf above the e0 in ten days interval during grain filling. SPAD measures were transformed to total chl and N conc. E0 leaf has been found more grain yield determining than e3 leaf and terminal grain filling duration has been found more determining than early grain filling from the standpoint of correlation of grain yield with chl, N conc and SPAD measure. From pooled variance analysis; SPAD and chl conc were not significant different in different 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 hybrids (Hybrids x Leaves x Ages). Thirteen top high grain yielding hybrids (HGYHs) 8, 12, 11, 13, 5, 6, 10, 1, 7, 14, 2, 9 and 15 were non-significant different from the standpoint of grain yield. The SPADs were in the non-significant range of 51-55 in e0 leaf in the duration from 95 to 125 d among the fifteen hybrids. Among the top four HGYHs 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 from e0 leaf relatively. Top five HGYHS 8, 12, 11, 5 and 6 except 13 among the top listed ten hybrids constantly maintained chl and N conc implying SPAD in 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. HGYH 8 had degraded soluble proteins and enzymes and chl in 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-grain filling duration for high grain yield. Instead, efficient reasonable decline of the soluble protein and chl conc during early to mid-grain filling also accelerate grain filling phenomena.

scholarly journals Dynamics of chlorophyll and N concentration on e0 and e3 leaves of maize hybrids in winter in subtropical region

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Soluble Protein ◽  
Red Light ◽  
Grain Filling ◽  
Soluble Proteins ◽  
Subtropical Region ◽  
Maize Hybrids ◽  
N Concentration ◽  
Single Cross ◽  
Grain Filling Duration

National maize productivity is very low in Nepal. Increase of the productivity is only possible through growing high grain yielding single cross hybrid maize cultivar. So, development and evaluation of maize hybrids are principal steps to select high grain yielding and superior hybrid for cultivar. For it, fifteen newly bred single cross hybrids of yellow maize were examined from the standpoint of chlorophyll (chl) dynamics and their effects on grain yield. 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, chl and N concentration (conc) implying RAT (red light absorbance-transmittance) SPAD measure were taken from the topmost ear (e0 or E0) and third (e3 or E3) leaf above the e0 in ten days interval during grain filling. SPAD measures were transformed to total chl and N conc. E0 leaf has been found more grain yield determining than e3 leaf and terminal grain filling duration has been found more determining than early grain filling from the standpoint of correlation of grain yield with chl, N conc and SPAD measure. From pooled variance analysis; SPAD and chl conc were not significant different in different 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 hybrids (Hybrids x Leaves x Ages). Thirteen top high grain yielding hybrids (HGYHs) 8, 12, 11, 13, 5, 6, 10, 1, 7, 14, 2, 9 and 15 were non-significant different from the standpoint of grain yield. The SPADs were in the non-significant range of 51-55 in e0 leaf in the duration from 95 to 125 d among the fifteen hybrids. Among the top four HGYHs 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 five HGYHs 8, 12, 11, 5 and 6 except 13 among the top listed ten hybrids 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. HGYH 8 had degraded soluble proteins and enzymes and chl 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-grain filling duration for high grain yield. Instead, diagnostic decline of the soluble protein and chl conc during early to mid-grain filling also accelerate grain filling phenomena.

scholarly journals Variability and interdependence of characteristics of maize hybrids of different vegetation lengths

2021 ◽  
Vol 27 (1) ◽  
pp. 7-16
Author(s):  
Miloš Krstić ◽  
Velimir Mladenov ◽  
Jelena Ovuka ◽  
Dušan Stanisavljević ◽  
Bojan Mitrović ◽  
...  
Keyword(s):  
Grain Yield ◽  
Complex Analysis ◽  
Phenotypic Variability ◽  
Correlation Coefficients ◽  
Negative Consequences ◽  
Maize Breeding ◽  
Important Place ◽  
Maize Hybrids ◽  
Important Field ◽  
The Difference

Maize is one of the most important field crops with broad genetic and phenotypic variations. It occupies an important place in agricultural production in the world as in Serbia. The main aim of maize breeding is to obtain new inbred lines, i.e. to identify new hybrid combinations that will surpass existing hybrids in terms of grain yield and other important traits. The aim of this study was to examine the phenotypic variability of 10 NS maize hybrids of different genetic bases and maturity groups in agroecological conditions in Rimski Šančevi, to consider the interdependence of grain yield and other tested traits using PCA and correlation analysis. The obtained results indicate a significant variation of all examined properties except for the ear length. The significance of the difference indicated by the F test was confirmed by the Duncan test. Correlation coefficients indicate a significant positive interdependence between the mass of 1000 grains and the ear length (r = 0.698). PCA analysis provided a more complex analysis of the interdependencies of the examined traits and grain yield. The highest yields were achieved by hybrids that simultaneously showed high values of several yield components. Yields ranged from 11,210 kg ha-1 in the G-10 hybrid (FAO 600), to 14,790 kg ha-1 in the G-3 hybrid (FAO 400). In this study, hybrids of earlier maturity achieved higher grain yields, mainly due to drought tolerance. Therefore, the goal is to create drought-tolerant maize hybrids that will successfully endure the negative consequences of global warming.

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.)

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Red Light ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Reaction Centers ◽  
Nutrient Mobilization ◽  
Maize Leaves ◽  
Light Absorbance

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.

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.)

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Dry Matter ◽  
Nitrogen Concentration ◽  
Red Light ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Reaction Centers ◽  
Nutrient Mobilization ◽  
Maize Leaves ◽  
Light Absorbance

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.

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.)

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Nitrogen Concentration ◽  
Red Light ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Reaction Centers ◽  
Extended Model ◽  
Nutrient Mobilization ◽  
Grain Yields ◽  
Maize Leaves

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.

scholarly journals Frequency distribution and mean comparisons of red light absorbance-transmittance of the e1 leaf sectors of five pipeline maize hybrids during early grain filling in subtropical winter

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Frequency Distribution ◽  
Flag Leaf ◽  
Red Light ◽  
Grain Filling ◽  
Fertility Level ◽  
Crop Species ◽  
Single Reading ◽  
Precision Evaluation ◽  
The Mean ◽  
Light Absorbance

Background: Crop scientist’s curiosities were to examine variation in photosynthetic sectors of grain filler leaf or flag leaf of any major crop species. Crop scientists including plant breeders too will be privileged from the findings. So it includes such precision evaluation of single cross pipeline hybrids of yellow maize before their release as cultivars. Materials and methods: For it, five pipeline hybrids were examined from two trials of RCBD trial that they were in a big research plot with uniform soil fertility level and with the same control environment. Each of the trials was conducted planting the seeds of the fifteen newly bred separate hybrids on October 3, 2012 exposing their flowering and early grain filling to the natural winter in the subtropical region in Nepal. Five plants of the pipeline hybrids of the fifteen plots of three replications were randomly selected and tagged from each of the fifteen plots of the five hybrids before tassel emergence. After about one month of anthesis, one hundred observations of red light absorbance-transmittance (RAT) measures were taken from chlorophyll meter ‘SPAD 502’ (Soil Plant Analysis Development) from the just-above-ear (e1) leaf of each of the selected plants of the hybrids in three days from 99 to 101 days after sowing (DAS). Results and discussion: From analysis of frequency distribution of the RAT SPAD measures of the e1 leaf sectors, it is not necessary that hybrids that demonstrates curve with high kurtosis always yield higher. Among the five hybrids, second highest grain yielding hybrid 112 had least leaf sectors of very low RAT SPAD measures. Besides, the hybrid 112 has been found least skewed and least peaked among the five hybrids. Furthermore, the hybrid 112 displayed least coefficient of variation and standard deviation among the 1500 RAT SPAD readings of its e1 leaf sectors. From the mean analysis through DMRT (Duncan Multiple Range Test), the twenty four averages have been found almost non-significant different among themselves inside each of the five hybrids. Single reading and four reading averages were non-significant different to one hundred reading average of each of the fifteen selected plants. Besides, the study also implies that a single reading from a leaf in the surrounding region of the topmost ear in five randomly selected plants can suffice to reflect the average SPAD measure of the particular leaf if the readings are from the e1 leaf. But, it can also be concluded that the similar non-significant nature of average central leaves around the top ear node. The mean comparison also gives useful information about the methodology of taking SPAD observations and how many readings are enough for the study of red light absorbance-transmittance, chl and N concentration in maize leaves. It also includes explanation why the e1 leaf is taken in the study.

scholarly journals Correlation and path analysis in recombinant inbred lines (RILs) of wheat (Trticum aestivum L.)

2016 ◽  
Vol 8 (2) ◽  
pp. 826-832
Author(s):  
Ramesh Ramesh ◽  
Shailesh Marker ◽  
S. Muniswamy ◽  
Yamanura Yamanura
Keyword(s):  
Grain Yield ◽  
Recombinant Inbred ◽  
Recombinant Inbred Lines ◽  
Flag Leaf ◽  
Correlation Coefficients ◽  
Grain Filling ◽  
Inbred Lines ◽  
Spike Length ◽  
Grain Filling Period ◽  
Selection Of

Correlation and path coefficient analysis were studied in 22 heat tolerant Recombinant Inbred Lines (RILs) of wheat. Analysis of variance revealed the significant difference among genotypes for all the characters. Suggested that there was ample scope for selection of promising RILs for yield improvement. A wide range of variability was exhibited by most of the traits. The results of correlation studies indicated that genotypic correlation coefficients were higher in magnitude than their corresponding phenotypic correlation coefficients for all the traits which indicated that association among these characters was under genetic control and indicating the preponderance of genetic variance in expression of characters. Grain yield per plant had high, significant and positive association with number of grains per spike, spike weight, spike length, canopy temperature depression, tillers per plant, grain filling period and chlorophyll content both at genotypic and phenotypic levels indicating that these traits were main yield attributing traits. Path analysis revealed that grains per spike, tillers per plant, spike length, had the highest positive direct effect on grain yield followed by flag leaf length, flag leaf width, days 50% heading, plant height, grain filling period, membrane stability and days to maturity at genotypic level. The selection of characters such as grains per spike, tillers per plant, spike length and spike weight would be helpful for further improvement in RILs of wheat.

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.)

2015 ◽  
Author(s):  
Nav Raj Adhikari ◽  
Surya Kant Ghimire ◽  
Shrawan Kumar Sah ◽  
Keshab Babu Koirala
Keyword(s):  
Grain Yield ◽  
Nitrogen Concentration ◽  
Red Light ◽  
Correlation Coefficients ◽  
Dry Weight ◽  
Reaction Centers ◽  
Extended Model ◽  
Nutrient Mobilization ◽  
Grain Yields ◽  
Maize Leaves

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.

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