SIGNIFICANCE OF CORRELATION BETWEEN DURA lION OF JUVENILE PERIOD AND EACH OF HEIGHT, EARlLlNESS AND PRODUCTIVITY CHARACTERS FOR EARLY SELECTION IN THE OWN ROOTED HYBRID TE ~ROSE SEEDLINGS

Two successive experiments were set up using stratified seeds collected
from a population of 2 and 3 years old-plants of Hybrid Tea-rose (Rosa hylirida, L.cv.
KardinaQ. Each experiment continued for 3 years in glasshouses. Seeds were sown in
plastic trays. individually transplanted In the cotyledon stage into 20 em dia!'1eter clay
pots and left until the time of the apical flower bud appearance. According td this time,
seedlings were divided into 12 and 11 categories in the 111 and 2nd experiments;
respectively. and planted in ground beds. The number of days from gerrrination to
flower bud appearance is defined as juvenile period. The relations between juvenile
period and some vegetative and flowering characters in the own rooted seedlings
were studied.
One year Old-seedlings. varying in juvenile periods, were budded on a
rootstoclc Rosa canina. Lcv. lnermis and the grafted plants were plantet( in ground
beds. The relations between some characters of the own rooted seedlings.land those
of the grafted plants were studied for 2 years. The results of the two expert ents can
be summarized as follows:
1- The leaf number at the flower bud appearance was 7 leaves.
2- The own rooted seedlings with short juvenile periods had shorter heigtits at both
times of flower bud appearance and first flowering, flowered eartier and produced
more flowers than those with tong juvenile periods. Significa~t positive
correlations were detected between the duration or the juvenile perio~ and each
of the height of the own rooted seedlings at flower bud appearance, the height at
first flowering either for the own rooted seedlings or for the 1 year Old-grafted
plants and ftowering time or the own root.ed seedlings. Also, significant positive
correlations were found between the own rooted seedlings height at flower bud
appearance and their height at first flowering.
3- Significant negative correlations were found between the juvenile peri?d and the
flower yield o( the rmn rooted seedlings. At first flowering, there wer significant
positive correlations between the height of the own rooted seedlin s and their
height on a rootstock.
4- There were significant positive correlations between the flower yield of the 1 year
old-own rooted seedlin,is and their yield in the 2nd year and also eir yield in
each of the 1 II and 2 year after grafting. The same situations we~e recorded
between the flower yield of the 2 years oId-own rooted seedlings and that o( the
grafted plants either in the 1" or in the 2td year after grafting. The flower yield of
the 1 year old-grafted plants and that of the 2 years old-grafted ones were
positively correlated.
5- " was clear Ihatthe juvenile period depends on the plant developme t and does
not control thi, process. The relations between the juvenile period and the
studied characters of the own rooted seedlings were probably largely inherent
 
and remained valid for the grafted plants. Selection was carried out firstly fo~
short juvenile period thai means for early flowering, secondarily (or long heigh
        and at the end for flower yield. The obtained results were discussed.