Abstract
Supplying both N forms (NH4++NO3−) to the maize (Zea mays L.) plant can optimize productivity by enhancing reproductive development. However, the physiological factors responsible for this enhancement have not been elucidated, and may include the supply of cytokinin, a growth-regulating substance. Therefore, field and gravel hydroponic studies were conducted to examine the effect of N form (NH4++NO3− versus predominantly NO3−) and exogenous cytokinin treatment (six foliar applications of 22 μM 6-benzylaminopurine (BAP) during vegetative growth versus untreated) on productivity and yield of maize. For untreated plants, NH4++NO3− nutrition increased grain yield by 11% and whole shoot N content by 6% compared with predominantly NO3−. Cytokinin application to NO3−-grown field plants increased grain yield to that of NH4++NO3−-grown plants, which was the result of enhanced dry matter partitioning to the grain and decreased kernel abortion. Likewise, hydroponically grown maize supplied with NH4++NO3− doubled anthesis earshoot weight, and enhanced the partitioning of dry matter to the shoot. NH4++NO3− nutrition also increased earshoot N content by 200%, and whole shoot N accumulation by 25%. During vegetative growth, NH4++NO3− plants had higher concentrations of endogenous cytokinins zeatin and zeatin riboside in root tips than NO3−-grown plants. Based on these data, we suggest that the enhanced earshoot and grain production of plants supplied with NH4++NO3− may be partly associated with an increased endogenous cytokinin supply.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 307-313 |
| Number of pages | 7 |
| Journal | Plant and Soil: An International Journal on Plant-Soil Relationships |
| Volume | 142 |
| Issue number | 2 |
| DOIs | |
| State | Published - May 1992 |
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Keywords
- cytokinin
- field
- greenhouse
- maize
- nitrogen form
ASJC Scopus subject areas
- Soil Science
- Plant Science
Cite this
Role of cytokinin in enhanced productivity of maize supplied with NH4+ and NO3−. / Smiciklas, K. D.; Below, F. E.
In: Plant and Soil: An International Journal on Plant-Soil Relationships, Vol. 142, No. 2, 05.1992, p. 307-313.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Role of cytokinin in enhanced productivity of maize supplied with NH4+ and NO3−
AU - Smiciklas, K. D.
AU - Below, F. E.
PY - 1992/5
Y1 - 1992/5
N2 - Supplying both N forms (NH4++NO3−) to the maize (Zea mays L.) plant can optimize productivity by enhancing reproductive development. However, the physiological factors responsible for this enhancement have not been elucidated, and may include the supply of cytokinin, a growth-regulating substance. Therefore, field and gravel hydroponic studies were conducted to examine the effect of N form (NH4++NO3− versus predominantly NO3−) and exogenous cytokinin treatment (six foliar applications of 22 μM 6-benzylaminopurine (BAP) during vegetative growth versus untreated) on productivity and yield of maize. For untreated plants, NH4++NO3− nutrition increased grain yield by 11% and whole shoot N content by 6% compared with predominantly NO3−. Cytokinin application to NO3−-grown field plants increased grain yield to that of NH4++NO3−-grown plants, which was the result of enhanced dry matter partitioning to the grain and decreased kernel abortion. Likewise, hydroponically grown maize supplied with NH4++NO3− doubled anthesis earshoot weight, and enhanced the partitioning of dry matter to the shoot. NH4++NO3− nutrition also increased earshoot N content by 200%, and whole shoot N accumulation by 25%. During vegetative growth, NH4++NO3− plants had higher concentrations of endogenous cytokinins zeatin and zeatin riboside in root tips than NO3−-grown plants. Based on these data, we suggest that the enhanced earshoot and grain production of plants supplied with NH4++NO3− may be partly associated with an increased endogenous cytokinin supply.
AB - Supplying both N forms (NH4++NO3−) to the maize (Zea mays L.) plant can optimize productivity by enhancing reproductive development. However, the physiological factors responsible for this enhancement have not been elucidated, and may include the supply of cytokinin, a growth-regulating substance. Therefore, field and gravel hydroponic studies were conducted to examine the effect of N form (NH4++NO3− versus predominantly NO3−) and exogenous cytokinin treatment (six foliar applications of 22 μM 6-benzylaminopurine (BAP) during vegetative growth versus untreated) on productivity and yield of maize. For untreated plants, NH4++NO3− nutrition increased grain yield by 11% and whole shoot N content by 6% compared with predominantly NO3−. Cytokinin application to NO3−-grown field plants increased grain yield to that of NH4++NO3−-grown plants, which was the result of enhanced dry matter partitioning to the grain and decreased kernel abortion. Likewise, hydroponically grown maize supplied with NH4++NO3− doubled anthesis earshoot weight, and enhanced the partitioning of dry matter to the shoot. NH4++NO3− nutrition also increased earshoot N content by 200%, and whole shoot N accumulation by 25%. During vegetative growth, NH4++NO3− plants had higher concentrations of endogenous cytokinins zeatin and zeatin riboside in root tips than NO3−-grown plants. Based on these data, we suggest that the enhanced earshoot and grain production of plants supplied with NH4++NO3− may be partly associated with an increased endogenous cytokinin supply.
KW - cytokinin
KW - field
KW - greenhouse
KW - maize
KW - nitrogen form
UR - http://www.scopus.com/inward/record.url?scp=51249162952&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=51249162952&partnerID=8YFLogxK
U2 - 10.1007/BF00010976
DO - 10.1007/BF00010976
M3 - Article
AN - SCOPUS:51249162952
VL - 142
SP - 307
EP - 313
JO - Plant and Soil
JF - Plant and Soil
SN - 0032-079X
IS - 2
ER -