2.1 Plant material and growth conditions
J. auriculatum plants were cultivated in the experimental field
of the department at Indian Institute of Technology Kharagpur, India.
All the experiments were carried out in the summer of 2018 and 2019
subsequently. The flowering occurs from May and lasts till August. The
average lowest and highest temperatures of the region during May-June
ranged between 24±3°C to 36±3°C respectively and the average relative
humidity during this period was around 78%, respectively. The in
situ experiments were carried on flowers of field-grown plants under
natural day-light conditions from six different floral maturation stages
namely, early bud: Stage 1 (S1), mid-bud: Stage 2 (S2), late bud: Stage
3 (S3), flower blooming: Stage 4 (S4), fully bloomed flower: Stage 5
(S5) and senescing flower: Stage 6 (S6). Flowers of S1 was observed one
day prior to flower blooming; S2 was observed at morning on the day of
flower blooming; S3 was in the afternoon on the day of flower blooming;
S4 was in the evening at the time of flower blooming; S5 was in the
night on the day of flower blooming; S6 was observed the next morning of
flower blooming.
For controlled-temperature related studies, the plants were acclimatized
for five days at particular air temperature in a growth chamber (LabTech
India Pvt. Ltd.). The plants were incubated under four different
temperature conditions 20°C, 25°C, 30°C and 35°C respectively,
where relative humidity of 70%,
light intensity of 2000 lux (maintained via cool white fluorescent
lamps) and 12h/ 12h (06.00 h - 18.00 h/ 18.00 h - 06.00
h) light/dark cycle was maintained.