Quality traits of maize inbred lines and hybrids with efficient photosynthetic functions (original) (raw)
Related papers
Proceedings for Natural Sciences Matica Srpska, 2012
This study confirmed our hypothesis that new maize inbred lines and hybrids derived from them had a dominant property of an efficient photosynthetic model. This property is successfully used in breeding programmes, modern technologies of the seed, and commercial maize production. This statement is supported by the results displayed on the erect position of the top leaves of new maize inbred lines and photosynthetic and florescence parameters: the change of the delayed chlorophyll fluorescence intensity during its course and dynamics, the Arrhenius criterion for the determination of critical temperatures (phase transition temperatures) and the activation energies, as a measure of conformational changes in chloroplasts and the thylakoid membrane. Furthermore, a grain structure including its physical and chemical parameters of new maize inbred lines and hybrids was analysed in the present study. In addition, relevant breeding, seed production and technological traits, properties and parameters of new maize inbred lines and maize hybrids were observed in the present study. The overall presented results show that properties of new inbred lines and maize hybrids are based on the nature of conformational and functional changes that occur in their chloroplasts and thylakoid membranes, as well as, on progressive effects in modern breeding, contemporary hybrid seed production, and the commercial maize production.
Genetika, 2008
Actual prestigious properties of maize inbred lines -a good initial basis for the efficient development of new and yielding maize hybrids. Vol. 40, No2,[121][122][123][124][125][126][127][128][129][130][131][132][133] This study conforms our hypothesis that there are elite maize inbred lines, which can be considered actual and prestigious as they have not only a property of the water status and a greater grain dry down rate during the maturation period, but also a property of the efficient photosynthetic-fluorescence model that is successfully used in the contemporary processes of breeding, and thereby in the development of new and yielding maize hybrids. Presented results obtained on the dynamics of grain dry down during the maturation period and on photosyntheticfluorescence parameters (temperature dependence of the chlorophyll delayed fluorescence intensity, the Arrhenius plot for the determination of critical 122 GENETIKA, Vol. 40, No. 2, 121 -133, 2008. temperatures, i.e. phase transition temperatures and the activation energy) show that properties of the observed inbreds are based on effects and nature of conformational and functional changes occurring in their thylakoid membranes and other chemical structures of grain tissues. Summarised results of studies on actual and prestigious properties of maize inbreds will contribute to more exact, rational and expeditious proceedings of contemporary processes of breeding.
Genetika, 2009
This study conforms the hypothesis that there are elite maize inbred lines with erect top leaves that have a property of an efficient photosynthetic model and that as such are successfully used in the processes of breeding in which the number of plants is increased per area unit (plant density). This proof was established by the application of non- invasive photosynthetic-fluorescence method suitable for the evaluation of the efficiency of the photosynthetic model. The obtained photosynthetic and fluorescence properties of observed prestigious maize inbred lines with the erect top leaves are based on the effects and the nature of changes in chlorophyll fluorescence occurring in their thylakoid membranes. Their principal parameters are temperature dependence of the chlorophyll delayed fluorescence intensity, the Arrhenius plot for the determination of the phase transition in thylakoid membranes and the estimated activation energies. The displayed results on the size of an angle betwe...
2016
The prestigious maize inbred lines with erect top leaves. the priority performance of the efficient photosynthetic model in breeding – Genetika, Vol. 41, No. 1, 41- 58. This study conforms the hypothesis that there are elite maize inbred lines with erect top leaves that have a property of an efficient photosynthetic model and that as such are successfully used in the processes of breeding in which the number of plants is increased per area unit (plant density). This proof was established by the application of non-invasive photosynthetic-fluorescence method suitable for the evaluation of the efficiency of the photosynthetic model. The obtained photosynthetic and fluorescence properties of observed prestigious maize inbred lines with the erect top leaves are based on the effects and the nature of changes in chlorophyll fluorescence occurring in their thylakoid membranes. Their principal parameters are temperature dependence of the chlorophyll delayed fluorescence intensity, the Arrhen...
Photosynthetica, 2005
We tested the usefulness of chlorophyll a fluorescence quenching analysis for the selection of maize parental inbred lines able to produce F, hybrids with a high CO2 assimilation rate during growth at suboptimal temperature. Fifty inbred lines, grown at 15 degrees C, showed at 6 degrees C a broad genetic variability regarding the quantum yield of photosynthetic electron transport (Phi(PS2)). A decrease of Phi(PS2) in sensitive lines was caused more by reduction of the efficiency of excitation energy capture by open photosystem 2 (PS2) reaction centres (F-v'/F-m') than by a drop in photochemical quenching (q(P)). Selected inbred lines with the highest (H) and the lowest (L) values of Phi(PS2) were used for separate crossings in a diallelic arrangement. Twenty-one of HxH hybrids and 21 of the LxL hybrids were grown at 15 degrees C. The HxH hybrids showed at suboptimal temperature a significantly higher transport of photosynthetic electrons than the LxL hybrids at lower (400) as well as at higher [800 mu mol(photon) m(-2) s(-1)] irradiance. The mean net photosynthetic rate (P-N) in HxH and LxL hybrids amounted to 8.4 and 5.8 (second leaf) and 8.5 and 7.6 mu mol(CO2) m(-2) s(- 1)(third leaf), respectively. Among the best 20 hybrids with regard to PN (values larger than the average) of second leaves, as many as 15 were derived from H lines (75 % of hybrids), whereas among the best 21 hybrids with regard to PN of the third leaves, 16 were derived from H lines (76 % of hybrids). The intensive PN of HxH hybrids was most often accompanied by less water lost via transpiration in relation to photosynthesis than in the hybrids of L lines. Hence an analysis of chlorophyll a fluorescence quenching enables the selection of inbred lines, which can produce hybrids with improved CO2 fixation and with efficient water management during growth at suboptimal temperature.
Photosynthetica, 2010
The response of selected photosynthetic and morphological parameters of plants to drought was examined in 5 inbred lines of maize (Zea mays L.) and their 10 F1 hybrids. The aim of the study was to establish whether the photosynthetic performance of parental genotypes under drought conditions correlates with the performance of their progeny and whether the net photosynthetic rate, the chlorophyll fluorescence parameters or the content of photosynthetic pigments could be used as reliable physiological markers for early breeding generations. The relative importance of the additive and the nonadditive (dominance, maternal) genetic effects in the inheritance of these parameters was also assessed by means of the quantitative genetics analysis. The results showed that the nonadditive genetic effects associated with a particular combination of genotypes or a particular direction of crossing are at least equally and often even more important as the additivity and that these genetic effects almost totally change with the exposure of plants to drought conditions. This was reflected in the inability to predict the response of F1 hybrids to drought on the basis of the photosynthetic performance of their parents, which indicates that the practical usability of such parameters in maize breeding programs is rather limited. quantum efficiency of photosystem II; g s -stomatal conductance; LSD -least significant difference; P N -net photosynthetic rate; PAR -photosynthetically active radiation; PS -photosystem; QTL -quantitative trait loci; Rubisco -ribulose-1,5-bisphosphate carboxylase/oxygenase; RuBP -ribulose-1,5-bisphosphate; RWC -relative water content; SLM -specific leaf mass; WUE -wateruse efficiency. Acknowledgements: The authors are grateful to B.Sc. students Lenka Fridrichová, Michal Andrle and Ilona Horáčková for their help with the measurements of the photosynthetic and morphological parameters of the plants, and to Dr. Jaroslav Poruba from the CEZEA Breeding Station at Čejč, Czech Republic, for the supply of maize kernels.
2015
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
Background and Purpose: Photosynthetic efficiency in crops can be associated with stress resistance and yield increase. In maize, photosynthetic efficiency is important in inbred lines during breeding process and in seed production, as well as in hybrids. Objective of this study is to determine differences in photosynthetic efficiency under the water-limited conditions between seven flint and dent maize inbred lines belonging to various heterotic groups. Moreover, this investigation will serve as a preliminary study for the QTL analysis of chlorophyll fluorescence parameters in order to understand the genetic and physiological background to drought stress tolerance in maize.
Post-anthesis changes in photosynthetic traits of maize hybrids released in different years
Changes in post-anthesis physiological attributes related to genetic improvement for grain-yield were studied for six Chinese maize (Zea mays L.) hybrids widely grown in North China during the past 50 years. The characteristics assessed included lightsaturated photosynthetic rate (P sat ), chlorophyll content, soluble protein content, maximal efficiency of PS2 photochemistry (F v / F m ), PS2 efficiency (F PS2 ), ribulose-1,5-bisphosphate carboxylase (RuBPCase) activity and phosphoenolpyruvate carboxylase (PEPCase) activity. We found that P sat of the newer hybrids was not always higher than the older ones. However, P sat of the 1950s hybrids was the highest among all at flowering stage, which was associated with their high PEPCase activity and soluble protein content. Post-anthesis changes in P sat of the older hybrids can be divided into two phases. During the first phase, which was the decisive phase of grain filling, P sat of the older hybrids declined gradually whereas the new hybrids remained relatively constant. P sat of 1950s hybrids was not the highest among all maize hybrids any longer although their PEPCase activities were also the highest. The reduction in P sat of the older hybrids during this phase was associated with a reduction in the chlorophyll content and the soluble protein content but was not influenced by the specific activity of RuBPCase and PEPCase. Adapting to the lowered CO 2 assimilation capacity, a down-regulation of F PS2 occurred in the older hybrids to protect the photosynthetic apparatus from photo-damage by strong light, while F v /F m only decreased slightly during this phase, suggesting a functional PS2 apparatus in senescent flag leaves. During the second phase, the older hybrids underwent an irreversible leaf senescence that certain photosynthetic traits declined substantially with P sat , whereas the photosynthetic components of the newer hybrids remained functional. Newer maize hybrids produced higher grain yield compared to the old ones mainly because they could remain photosynthetically active when the older hybrids aged during the grain-filling period. The decline in photosynthetic rate of older hybrids during senescence is generally attributed to the degradation of both structural and functional components of chloroplasts. #
Yield formation in maize hybrids of different ‘stay-green’rating
Remobilisation of nitrogen reserves from the leaves to the grain during the postsilking growth phase in maize leads to leaf senescence. This may result in a decline in the radiation use efficiency and restrict the attainment of potential yield. 'Staygreen' (sgr) hybrids have been selected in New Zealand with the expectation that they may have reduced post-silking leaf senescence. In this study the influence of fertiliser nitrogen on leaf senescence and yield component formation was quantified in four hybrids described as having low (sgr 6) to high (sgr 9), 'stay-green' ratings. Fertiliser N (270 kg N ha -1 ) increased green leaf area per plant at silking by 36% while 'P38V12' (sgr 7) had 20% more leaf area per plant than 'P38F70' (sgr 8). Nitrogen also reduced the number of senesced leaves during the reproductive phase and enabled the 'stay-green' trait to be expressed. By the start of grain filling, 'P38V12' (sgr 7) had intercepted 510 MJ m -2 of photosynthetically active radiation (PAR) which was 11% more than that intercepted by 'P38F70' (sgr 8). This early advantage in PAR interception was maintained in absolute terms during the postsilking phase but no biomass yield advantage was recorded. The presence of added N increased the number of kernels by 50% from 280 to 420 per ear. The rachis of 'P38V12' (sgr 7) carried 410 kernels compared with 340 for each of the other hybrids. This was offset by the 1000 seed weight of 'P38V12' (sgr 7) of 240 g which was 25% lower than 'P38F70' (sgr 8). In this study the potential grain yield was set during the vegetative growth phase, but actual grain yield achieved was influenced by post-silking growth. Overall the 'stay-green' trait was exhibited in the presence of added nitrogen but did not influence total dry matter or grain yield.