Cross-pollination effects on maize (Zea mays L.) hybrid yields

1992 ◽  
Vol 72 (1) ◽  
pp. 27-33 ◽  
Author(s):  
R. T. Weiland
Keyword(s):  
Zea Mays ◽  
Zea Mays L ◽  
Grain Filling ◽  
Maize Yield ◽  
Kernel Weight ◽  
First Year ◽  
Kernel Number ◽  
Cross Pollination ◽  
Grain Filling Period ◽  
N Fertility

Recent studies have shown that pollen from a long-season maize (Zea mays L.) hybrid increased yield of a short-season hybrid by lengthening the effective grain-filling period, while the reciprocal cross did not alter this period or yield. This effect (metaxenia) was evaluated further in the studies reported here with hybrids of more diverse maturity and under both high and low N fertility. In the first year of this study (1989), sib- and cross-pollinations were made among B73Ht × Mo17 (B × 7) and two early-silking hybrids, LH59 × LH146 (L × 6) and Pioneer 3732 (3732) under N-sufficient (275 kg ha−1) and two lower N regimes (17 and 67 kg ha−1). Only a few significant effects were observed and these were noted at high N with one exception. With 3732 pollen, grain yield of B × 7 was decreased at 275 kg N ha−1, and physiological maturity occurred 3 d earlier. Yield of 3732 was increased by L × 6 pollen in comparison with B × 7 pollen. Kernel number and average kernel weight were not altered by pollen source. Pollen type did not affect yields under low N fertility, except for a reduction when B × 7 was pollinated by L × 6 at the 67-kg N ha−1 rate. In 1990, under N-sufficient fertility, B73Ht × LH156 (B × 6), a late-silking hybrid, and LH146 × LH82 (L × 2), an earlier hybrid, were sib- and cross-pollinated with B × 7 and 3732. The only significant effect observed was that L × 2 pollen increased B × 6 yield. Thus with the hybrids used, yields of early-season types were not altered by cross-pollination with long-season types. Previous results showing increased yields when 3732 was pollinated by B × 7 were not duplicated in either year, suggesting metaxenia effects are highly dependent upon environment.Key words: Metaxenia, xenia, cross-pollination, maize, yield, N levels

HERITABILITIES AND RELATIONSHIPS AMONG GRAIN-FILLING PERIOD, SEED WEIGHT AND QUALITY IN FORTY ITALIAN VARIETIES OF CORN (ZEA MAYS L.)

1980 ◽  
Vol 60 (4) ◽  
pp. 1101-1107 ◽  
Author(s):  
M. PERENZIN ◽  
F. FERRARI ◽  
M. MOTTO
Keyword(s):  
Zea Mays ◽  
Seed Weight ◽  
Zea Mays L ◽  
Grain Filling ◽  
Kernel Weight ◽  
Genotypic Differences ◽  
Dry Matter Accumulation ◽  
Grain Moisture ◽  
Wide Range ◽  
Grain Filling Period

Forty Italian open-pollinated varieties of corn (Zea mays L.), selected to represent a wide range of plant maturity and grain weight, were evaluated in 1977 and 1978 to determine genetic variances and heritabilities for length and rate of grain-filling period, kernel weight and three seed-quality traits and to examine relationships among these traits. The results showed highly significant genotypic differences and high heritability estimates for most of the traits studied. Moreover, kernel weight and rate of grain filling were found to be closely associated, although this relationship could not be statistically tested. A relatively high correlation was also detected between kernel weight and length of the grain-filling period. The increase in seed weight obtained through a delay in black-layer formation was associated with a higher grain moisture content and a decreased grain protein percentage. A further noteworthy finding of this study was the identification of two varieties which attained a large seed weight in a relatively short time through a very high rate of dry matter accumulation. The implications of these findings are discussed from a physiological and breeding point of view.

Kernel weight dependence upon plant growth at different grain-filling stages in maize and sorghum

2008 ◽  
Vol 59 (3) ◽  
pp. 280 ◽  
Author(s):  
Brenda L. Gambín ◽  
Lucas Borrás ◽  
María E. Otegui
Keyword(s):  
Plant Growth ◽  
Developmental Stages ◽  
Environmental Variability ◽  
Grain Filling ◽  
Kernel Weight ◽  
Kernel Number ◽  
Kernel Size ◽  
Simple Estimate ◽  
Kernel Set ◽  
Grain Filling Period

In the present study we tested how assimilate availability per kernel at different grain-filling stages may affect maize (Zea mays L.) and sorghum (Sorghum bicolor L. Moench) individual kernel weight (KW). These two species have shown a contrasting KW response to increased assimilate availability at similar seed developmental stages. Plant growth rate (PGR) per kernel was used to estimate the assimilate availability per kernel at two stages: around the early grain-filling period when kernel number per plant is also being established, and around the effective grain-filling period. We tested 3 commercial genotypes from each species, and modified the PGR by thinning or shading the stand at different developmental stages. In both species, each genotype showed a particular relationship between PGR around flowering and kernel number, which gave a range of responses in the PGR per kernel set around flowering. Final KW always increased whenever PGR per kernel around flowering was enhanced. Only sorghum showed a consistent KW increase when PGR per kernel during the effective grain-filling period was enhanced. Results confirmed that increasing assimilate availability per kernel will affect maize kernel size only if the potential set early in development is altered. Most important, we showed that linking specific KW sensibility across species at different seed developmental stages using a simple estimate of assimilate availability per seed (i.e. PGR per kernel) at each grain-filling stage helped explain most of the explored genotypic and environmental variability in final kernel size.

scholarly journals Differential Maize Yield Hybrid Responses to Stand Density Are Correlated to Their Response to Radiation Reductions Around Flowering

2022 ◽  
Vol 12 ◽  
Author(s):  
Federico H. Larrosa ◽  
Lucas Borrás
Keyword(s):  
Yield Components ◽  
Stand Density ◽  
Grain Filling ◽  
Maize Yield ◽  
Kernel Weight ◽  
Yield Component ◽  
Physiological Parameters ◽  
Yield Response ◽  
Genotypic Differences ◽  
Kernel Number

Altered stand density affects maize yields by producing changes in both numerical yield components, kernel number per plant (KNP), and kernel weight (KW). Kernel number is determined by the accumulation of ear biomass during the flowering period, whereas KW is determined by the sink potential established during flowering and the capacity of the plant to fulfill this potential during effective grain filling. Here, we tested if different short shading treatments during different stages around flowering can help discriminate genotypic differences in eco-physiological parameters relevant for maize stand density yield response and associated yield components. Our specific objectives were to: (i) identify hybrids with differential shading stress response, (ii) explore shading effects over eco-physiological parameters mechanistically related to KNP and KW, and (iii) test if shading stress can be used for detecting differential genotypic yield responses to stand density. The objectives were tested using four commercial maize hybrids. Results indicated that KNP was the yield component most related to yield changes across the different shading treatments, and that the specific shading imposed soon after anthesis generated the highest yield reductions. Hybrids less sensitive to shading stress were those that reduced their plant growth rate the least and the ones that accumulated more ear biomass during flowering. Genotype susceptibility to shading stress around flowering was correlated to stand density responses. This indicated that specific shading stress treatments are a useful tool to phenotype for differential stand density responses of commercial hybrids.

EFFECT OF TEMPERATURE DURING GRAIN FILLING ON WHOLE PLANT AND GRAIN YIELD IN MAIZE (Zea mays L.)

1983 ◽  
Vol 63 (2) ◽  
pp. 357-363 ◽  
Author(s):  
B. BADU-APRAKU ◽  
R. B. HUNTER ◽  
M. TOLLENAAR
Keyword(s):  
Zea Mays ◽  
Grain Yield ◽  
Leaf Senescence ◽  
Zea Mays L ◽  
Growth Yield ◽  
Grain Filling ◽  
Kernel Weight ◽  
Effect Of Temperature ◽  
Plant Parts ◽  
Whole Plant

In a 2-yr study, plants of an adapted, short-season single cross maize (Zea mays L.) hybrid were grown outdoors until 18 days post-silking. At that stage, the plants were transferred to controlled-environment growth cabinets where temperature effects on leaf senescence, grain and whole plant dry matter (DM) production and DM distribution were studied. The day/night temperature regimes were 25/15 °C, 25/25 °C, 35/15 °C and 35/25 °C. Higher temperatures reduced whole plant DM accumulation during grain filling. The reduction in DM accumulation was primarily related to a reduction in the period of time from 18 days post-silking until 100% leaf senescence and, to a limited extent, to a lower rate of whole plant DM production. Grain yield per plant was also lower under higher temperatures. The decreases in grain yield were almost entirely determined by a shorter duration of grain filling, while no temperature effect was observed on kernel growth rates or on kernel number per ear. During rapid grain filling, the increase in kernel DM results from utilization of a combination of assimilates temporarily stored in the vegetative plant parts and assimilates produced through current photosynthesis. Under the highest temperature regime, assimilates remobilized from other plant parts accounted for a greater proportion of kernel weight gain. In addition, there was an indication that higher night temperatures resulted in an increased proportion of gain in kernel weight resulting from remobilization of stored DM.Key words: Corn, temperature, grain-filling period, grain growth, yield components, leaf senescence

GROWTH AND [14C] SUCROSE UPTAKE OF APICAL AND BASAL MAIZE KERNELS

1986 ◽  
Vol 66 (4) ◽  
pp. 863-869
Author(s):  
JONATHAN M. GREENBERG ◽  
TIM LLOYD SETTER
Keyword(s):  
Zea Mays ◽  
Liquid Scintillation ◽  
Zea Mays L ◽  
Dry Weight ◽  
Grain Filling ◽  
Kernel Weight ◽  
Sucrose Uptake ◽  
Sucrose Transport ◽  
The Difference ◽  
Maize Kernels

Kernels located near the apex of the ear of corn (Zea mays L.) are smaller and more likely to abort than basal kernels. Studies were conducted to evaluate the importance of time of pollination and rate of sucrose uptake in determining differences in mature kernel weight between apical and basal kernels. Simultaneous pollination of all florets in an ear did not reduce the difference in mature dry weight between apical and basal kernels or the incidences of sterility and abortion. The ability of developing apical and basal kernels to take up sucrose was evaluated by immersing the bases of detached kernels in 50 mM 14C-sucrose and measuring the incorporated radioactivity by liquid scintillation counting. Sucrose uptake increased during development, especially at the beginning of the linear phase of grain filling. Differences in sucrose uptake rate were insufficient to explain the differences between apical and basal kernels in dry weight.Key words: Carbohydrate, partitioning, corn, sucrose transport, seed development, Zea mays L.

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