Q.If one can induce parthenocarpy through the application of growth substances, which fruits would you select to induce parthenocarpy and why?

To induce parthenocarpy, you would select fruits that naturally develop from an ovary but are normally dependent on fertilisation for fruit set. The key is to apply growth substances that mimic the hormonal signals pollination and fertilisation would provide.

The NCERT textbook specifically mentions that auxins can be used to induce parthenocarpy. You would choose fruits like tomatoes, cucumbers, and grapes for this purpose. The reason is straightforward: these fruits are commercially important, and seedless varieties are highly valued by consumers. By applying auxin to the unfertilised ovary, you trigger fruit development without the need for pollination or seed formation. …

Parthenocarpy is a fascinating biological process where fruits develop without the need for fertilisation. In nature, this occurs in some plants like bananas, grapes, and oranges, giving us seedless varieties. But what if we could artificially induce this in other fruits? That is exactly what plant growth regulators — especially auxins and gibberellins — allow us to do. By applying these substances to the ovary or flower, we can trick the plant into thinking fertilisation has occurred, triggering fruit development without seeds.

Now, which fruits would you select for such an experiment? The choice depends on two key factors: the fruit’s natural tendency toward seedlessness and the economic or practical benefit of seedless fruits.

First, consider fruits that already have some seedless varieties or are known to respond well to growth substances. For example, tomatoes are a classic candidate. They are widely consumed, and seedless tomatoes would be easier to process into sauces and pastes. More importantly, tomato ovaries are highly responsive to auxins like 2,4-D or NAA, which can induce parthenocarpy reliably. Similarly, eggplants (brinjal) and cucumbers are excellent choices — they are often grown for their fruit, and seedlessness improves texture and reduces bitterness.

Second, think about fruits where seeds are a nuisance or reduce market value. Watermelons are a prime example. Seedless watermelons are already popular, but they require complex breeding. Inducing parthenocarpy with gibberellins could simplify production. Likewise, grapes — many seedless varieties exist, but applying gibberellic acid can enhance fruit size and ensure seedlessness in otherwise seedy types.

Third, consider fruits that are naturally parthenocarpic but could benefit from hormonal induction to improve yield or uniformity. Bananas are already seedless, but they are sterile triploids — no induction needed. However, for oranges and lemons, some varieties are seedless, and growth substances can help maintain that trait under stress conditions.