Abstract
Three experiments were conducted for identification and characterization of high
yielding, early and late litchi germplasm, floral biology and pollen storage of litchi
during 2017 to 2019. Twenty five accessions of litchi were selected in different litchi
growing districts viz. Dinajpur, Thakurgoan, Kishoregonj, Khagrachari and Gazipur.
Experiment on floral biology was conducted at the field of HRC, BARI, Gazipur and
characterization of fruit tree was done in the existing location. Chemical characteristic
and related data were taken in the laboratory of Postharvest Section of HRC, pollen
viability test were done at the laboratory of Plant Pathology Division, BARI. The results
revealed that out of 25 litchi accessions, the most early season maturity accession was
LC22 (BARI Litchi-1) while the late maturity accessions was LC23 and LC45 (BARI
Litchi-2 and Kathali respectively). The highest fruit yield per tree (90.92 kg) was found
in LC36 (Gulabi). The maximum individual fruit weight was recorded in LC30 (36.56 g)
and minimum fruit weight was recorded in LC37 (13.59 g). The highest aril weight was
recorded in LC21 (26.40 g) and the lowest aril weight was recorded in LC32 (7.93 g). The
seed weight was maximum in LC29 (5.42 g) and minimum in LC24 (1.36 g). The highest
total sugar content was recorded in LC21 (21.70%) and the lowest total sugar content
was recorded in LC37 (8.90%). Average vitamin C content of litchi pulp was noted 21.13
mg/100 g. The highest total soluble solid was found in LC27 (18.63°Brix). The
development of panicle was divided into nine different stages. Maximum days required
for flowering in Kadmi (51.02 days) followed by Kathali (45.77 days) and BARI Litchi-4
(37.37 days). The shortest flowering time was recorded in BARI Litchi-2 (31.13 days).
The first phase of flowering was dominated by male (M₁) flower, second phase with
female (F) and third phase with M2 flowers. First flowering was recorded in Kadmi (25th
February), second in BARI Litchi-4 (26th February) and then BARI Litchi-2 (5th March)
and Kathali (13th March). The duration of male flower (M₁) was recorded 5, 5, 6 and 7
days BARI Litchi-2, BARI Litchi-4, Kathali and Kadmi, respectively. The longest
flowering period was recorded in Kadmi (23 days) followed by BARI Litchi-4 (20 days),
Kathali (19 days) and BARI Litchi-2 (18 days). Sex ratio differed significantly among the
germplasm and BARI Litchi-2 showed the highest (2.97) male to female ratio while the
lowest (1.99) male to female ratio was shown in Kadmi. Duration of stigma was found
the highest in Kadmi (59.33±1.53 hrs). The fruit weight of BARI Litchi-4 increased slowly
from 10 days to 30 DAFS and then increased sharply up to harvest. All the germplasm
showed rapid drop of fruit per panicle uo to 30 DAFS and decreased slowly. Pollen
remained viable in petri dish and desiccators (25-30°C) up to 7 days, 60 days in
refrigerator (5±7°C) and 90 days in deep freezer (20±5°C). Litchi pollen preserved in -
80±5°C for 1 year and maximum 24.53% and 54.19% pollen germination was recorded in
BARI Litchi-1 while minimum 19.14% and 45.65% pollen germination were observed in
BARI Litchi-2 from M1 and M2 pollen respectively.