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.)
Authors: Adhikari Nav Raj , Ghimire Surya Kant , Sah Shrawan Kumar , Koirala Keshab Babu 
Published: January 2018

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.