Articles
JUVENILITY OF APPLE SEEDLINGS: CORRELATION BETWEEN TREE GROWTH HABIT AND FLOWERING INDEX ON DIFFERENT APPLE PROGENIES AT THE MIDDLE WEST OF SANTA CATARINA STATE – BRAZIL
Article number
872_23
Pages
181 – 186
Language
English
Abstract
Around the World many investigations have already been done to overcome the challenge of the long juvenile period of apple seedlings.
To collaborate with apple breeders, a study has been done at Epagri / Caçador Experimental Station in order to investigate the correlation between some parameters of tree growth habit with juvenility phase on apple, expressed as flowering index – FI. After three and a half years from seed germination, a total of 1.287 pre-selections from eight apple progenies grafted on Marubakaido/M-9 inter-stem have been investigated.
The following variables were evaluated: a) plant height – PH; b) length of the last annual growth of the leader – AGL; c) length of the internodes – IL; d) type of leader – TL. Only for TL a reasonable good correlation with FI was observed.
There was significant negative correlation between length/thinness of the leader and intensity of blooming on all the eight apple progenies studied.
The correlation values varied from R=0,27 for the progeny Imperatriz × Fred Hough to R=0,49 for Imperatriz × M-46/94, Imperatriz × Catarina and Imperatriz × Baronesa, with an average value of R=0,44. For all the other variables, the correlation was very poor, even not significant in most cases.
For plant height, mentioned in the literature as a good parameter for selecting apple seedlings to shorten juvenile period, not only a very poor correlation with FI was observed, but even some negative correlation between both.
The average for all progenies for this parameter was R=0,07 only, being not significant.
For internodes length, even showing a negative correlation for all progenies as expected, the correlation values were highly variable.
The highest negative correlation was observed for the progeny Imperatriz × M-46/94 – R=-0,42 – and the poorest for the progeny M-72/90 × Gala – R=-0,017. These results indicate that for apple progenies grafted on Marubakaido/M-9 inter-stem, the only criterion that offers a certain guarantee for pre-selections leading to a short juvenile period on apple seedlings seems to be the type of leader.
To collaborate with apple breeders, a study has been done at Epagri / Caçador Experimental Station in order to investigate the correlation between some parameters of tree growth habit with juvenility phase on apple, expressed as flowering index – FI. After three and a half years from seed germination, a total of 1.287 pre-selections from eight apple progenies grafted on Marubakaido/M-9 inter-stem have been investigated.
The following variables were evaluated: a) plant height – PH; b) length of the last annual growth of the leader – AGL; c) length of the internodes – IL; d) type of leader – TL. Only for TL a reasonable good correlation with FI was observed.
There was significant negative correlation between length/thinness of the leader and intensity of blooming on all the eight apple progenies studied.
The correlation values varied from R=0,27 for the progeny Imperatriz × Fred Hough to R=0,49 for Imperatriz × M-46/94, Imperatriz × Catarina and Imperatriz × Baronesa, with an average value of R=0,44. For all the other variables, the correlation was very poor, even not significant in most cases.
For plant height, mentioned in the literature as a good parameter for selecting apple seedlings to shorten juvenile period, not only a very poor correlation with FI was observed, but even some negative correlation between both.
The average for all progenies for this parameter was R=0,07 only, being not significant.
For internodes length, even showing a negative correlation for all progenies as expected, the correlation values were highly variable.
The highest negative correlation was observed for the progeny Imperatriz × M-46/94 – R=-0,42 – and the poorest for the progeny M-72/90 × Gala – R=-0,017. These results indicate that for apple progenies grafted on Marubakaido/M-9 inter-stem, the only criterion that offers a certain guarantee for pre-selections leading to a short juvenile period on apple seedlings seems to be the type of leader.
Authors
F. Denardi, O. Berton, H. Stuker
Keywords
Malus × domestica, Borkh., apple breeding, pre-selection
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