Genetic Analysis of Inbred and Hybrid Grain Yield under Stress and Nonstress Environments in Tropical Maize

Crop Science ◽  
2003 ◽  
Vol 43 (3) ◽  
pp. 807 ◽  
Author(s):  
F. J. Betrán ◽  
D. Beck ◽  
M. Bänziger ◽  
G. O. Edmeades
Crop Science ◽  
2003 ◽  
Vol 43 (3) ◽  
pp. 807-817 ◽  
Author(s):  
F. J. Betrán ◽  
D. Beck ◽  
M. Bänziger ◽  
G. O. Edmeades

2008 ◽  
Vol 43 (7) ◽  
pp. 893-901 ◽  
Author(s):  
Sidney Netto Parentoni ◽  
Claudio Lopes de Souza Júnior

The objective of this work was to determine the relative importance of phosphorus acquisition efficiency (PAE - plant P uptake per soil available P), and phosphorus internal utilization efficiency (PUTIL - grain yield per P uptake) in the P use efficiency (PUE - grain yield per soil available P), on 28 tropical maize genotypes evaluated at three low P and two high P environments. PAE was almost two times more important than PUTIL to explain the variability observed in PUE, at low P environments, and three times more important at high P environments. These results indicate that maize breeding programs, to increase PUE in these environments, should use selection index with higher weights for PAE than for PUTIL. The correlation between these two traits showed no significance at low or at high P environments, which indicates that selection in one of these traits would not affect the other. The main component of PUTIL was P quotient of utilization (grain yield per grain P) and not the P harvest index (grain P per P uptake). Selection to reduce grain P concentration should increase the quotient of utilization and consequently increase PUTIL.


2019 ◽  
Vol 13 ((04) 2019) ◽  
pp. 536-545 ◽  
Author(s):  
Jewel Jameeta Noor ◽  
M.T. Vinayan ◽  
Shahid Umar ◽  
Pooja Devi ◽  
Muhammad Iqbal ◽  
...  

Heat stress resilience has emerged as an important trait in maize hybrids targeted for post–monsoon spring cultivation in large parts of South Asia and many other parts of the tropics. Selection based on grain yield alone under heat stress is often misleading, and therefore an approach involving stress-adaptive secondary traits along with grain yield could help in the development of improved, stable heat stress tolerant cultivars. We attempted to identify reliable and effective secondary traits associated with heat stress tolerance in tropical maize and sources of heat stress tolerant germplasm. A panel of 99 elite maize inbred lines representing the wider genetic diversity of tropical maize and a set of 58 elite hybrids were phenotyped under natural heat stress and optimal temperature for grain yield and 15 secondary traits including 10 morpho-physiological traits and 5 yield attributes. Evaluation under natural heat stress was done during the spring season by adjusting the planting date so that the complete reproductive stage (from tassel emergence to late grain filling) was exposed to heat stress. The optimal temperature trial was planted during the monsoon season with no exposure to heat stress at any crop stage. Heat stress significantly affected most of the observed traits. Among the traits studied two yield attributing traits, i.e.- ears per plant (EPP) and kernel per row (KPR), and three morpho-physiological traits, i.e.- chlorophyll content (CC), leaf firing (LF) and tassel blast (TB) were found to be the key secondary traits associated with grain yield under heat stress. In addition, low anthesis-silking internal (ASI) is an important trait that needs to be added in the index selection for heat stress tolerance. The study identified nine promising heat stress tolerant maize inbred lines with desirable secondary traits and grain yield under severe heat stress, which could be used as source germplasm in heat stress tolerance maize breeding program.


Crop Science ◽  
2015 ◽  
Vol 55 (2) ◽  
pp. 610-623 ◽  
Author(s):  
Beatrice E Ifie ◽  
Baffour Badu-Apraku ◽  
Vernon Gracen ◽  
Eric Y Danquah

Crop Science ◽  
2018 ◽  
Vol 58 (6) ◽  
pp. 2360-2369
Author(s):  
Adesike O. Kolawole ◽  
Abebe Menkir ◽  
Essie Blay ◽  
Kwadwo Ofori ◽  
Jennifer G. Kling

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