dalbergia

PowerPoint Presentation: 

Satheesh Naik S. J. First Ph. D. Dept of genetics and plant breeding

Seed abortion in multi-ovulated species: 

Seed abortion in multi-ovulated species Several multi-ovulated species shows positively skewed distribution of seeds per pods Could be 1. pre-fertilization regulation 2. selective elimination of pods 3. post fertilization abortion Tested these possibilities in Dalbergia sissoo and showed that intra-pod seed abortion resulting from intense sibling rivalry causes the observed PSSD.

Seed abortion in wind dispersed pods of Dalbergia sissoo : 

Seed abortion in wind dispersed pods of Dalbergia sissoo Dalbergia sissoo-erect growing deciduous tree native to the Indian Subcontinent Produces the flat ellipsoid fruits that are dispersed by wind. maternal regulation or sibling rivalry,,,,?????

Data on following characters : 

Data on following characters Wing loading Vertical settling velocity and horizontal dispersal distance Intra-pod seed abortion with age Selective abortions of pods Histological studies Pod tip excision experiments Effect of extract of maternal tissue and developing seed on embryo abortion

Fig. 1. Frequency distribution of the seeds per pod: 

Fig. 1. Frequency distribution of the seeds per pod Positively skewed cost of package is more Wing loading ratio increased From 10.11+_ 2.75 mg/cm2 (1 Seeded pods) to 14. 73+_2.02 mg/cm2 (3 seeded pods) this indicates that As seed number increase pod surface Area increased less rapidly

The skewed Seed distribution pattern could not be explained by the pollen grain limitation, ovule number, post fertilization pod abortion: 

The skewed Seed distribution pattern could not be explained by the pollen grain limitation, ovule number, post fertilization pod abortion Ovule number- normally distributed around the mean of 4.25+_0.62 seed number- positively skewed with a mean of 1.2+_ 0.56 An average there were about 116+_12.54 pollen grains per stigma of this 60% get germinated & penetrated into style. # Ovule number/ seed number % pods Contd …

PowerPoint Presentation: 

Post fertilization abortion of the pods was also random. Without any selective elimination of many seeded pods Progressive abortion of developing seeds in the pod appeared and frequencies of few seeded pods increases by the end of fourth week after pollination and frequency of seeds per shift towards positive skew. Contd … Seeds per pods % pods 1 2 3 4 Seeds per pods 1 2 3 4 1 2 3 4 1 2 3 4 10 20 30 20 40 60 80 2 nd week 3 rd week 4 th week

PowerPoint Presentation: 

Intra-pod seed abortion proceeds from base to tip. The dominant seed (pistil tip) may cause abortion of the basal seed either by starving or abortive chemical. abortive chemical was an indole derivative. hours 0 24 48 72 20 40 60 % abortion of young developing embryo Progress of abortion of young developing embryos as affected by extracts of good developing seeds Good embryo Aborted embryo tissue water

conclusion: 

conclusion This skewed seed distribution is the consequence of conflict of interest between parent and the offspring.