The INCORRECT statement is (4) The crop plant should necessarily have an optimized robust system for production of doubled haploids.

Option-wise explanation

• (1) “Allelic diversity for traits of interest should be available in the naturally occurring crossable germplasm” – Correct

  • Molecular breeding still relies on genetic variation.

  • If useful alleles exist in crossable germplasm, they can be tracked with markers and combined efficiently.

• (2) “The genes of interest cannot be derived from a sexually incompatible organism” – Correct as a statement about molecular breeding here

  • Classical “molecular breeding” or marker-assisted breeding typically shuffles alleles within crossable germplasm.

  • Genes from sexually incompatible species would fall under transgenic/GM approaches, not standard marker-assisted breeding.

• (3) “Availability of markers and linkage maps would facilitate the breeding program” – Correct

  • Molecular breeding depends on DNA markers linked to QTL/genes and linkage maps to perform MAS, QTL mapping, genomic selection, etc.

• (4) “The crop plant should necessarily have an optimized robust system for production of doubled haploids” – Incorrect

  • Doubled haploids are very useful for quickly creating fully homozygous lines, but many successful molecular breeding programs operate without a DH system.

  • DH technology is advantageous, not an absolute requirement; therefore, claiming it is “necessarily” needed is wrong.

So, the only incorrect requirement among the options is statement (4).