(Fe)male conflict
Often we see some fruits (like citrus) with multi-locular, while some are with single (as in Jamun). Well, typically in a multilocular, all the seeds in individual locule were nourished uniformly, meaning all the produced ovules formed were "taken care" by the ovary (female). In Jamun, although there were many ovules, only the dominant ovule takes the lead, expands and destroys the other ovules, hence only one becomes the seed. Let's park this aside for a while and see this from the perspective of survival.
The very objective of every species on earth is to survive & perpetuate its own copy. Carefully looking at it, this also applies to genders. Female (plant or animal) contributes >70% to its babies, while male contributes <30%. Female, although being polyphagous (mate with multiple males), it needs to "take care" of all of its progenies due to the >70% contribution. To be very precise, from the perspective of female, all the babies are the representative of Female. In contrast, from the perspective of male, only one dominant baby (came from its pollen or sperm) is the representative, hence only that baby is to be established and not other babies arising from same female. Hence, every male sends the genic signals to its "own" baby to compete (or kill) other babies. This is the *origin of ♂ ⟷ ♀ conflict*. When I say, conflict, it is only from our cultural perceptive. In a biological evolution, this is just a gender competition.
Having said that, let's look at a fruit.