In lathyrus odoratus homozygous blue colored flower, long pollen plant was cross with red colored flower,round flower plant. the F1 plants are test crossed and give rise to 720 seeds. on sowing tese seeds how many of their offsprings plants will be blue colored with round pollen

Dear student,
Please find below the solution to the asked query

The correct term should be red colored flower and round pollen plant.

In Lathyrus odoratus blue flower (B) is dominant over the red flower (b) and long pollen (L) dominant over round pollen (l).
Pea plant having Blue flower (BB) with Long pollen (LL) and Red flower (bb) with round pollen (ll).
 
Parent generation   :      BBLL (Blue-Long)          ×          bbll (Red-Round)

Gamete                  :                  BL                                               bl

​F₁ generation        :                                      BbLl (Blue flower-Long pollen) 

When F₁ hybrid plants are test crossed we will get:

Test Cross:                            
                                                               BbLl               ×              bbll    

Gametes                                         BL, Bl, bL, bl                           bl                

Progeny:                                                BbLl  ,  Bbll  ,  bL,   bbll

​Phenotypic ratio =        1 (Blue Long) : 1(Blue round) : 1(Red Long) : 1(Red Round)

Hence, one individual among four is blue flowered and round pollen plant.
Now, Total number of seeds produced is = 720

Therefore, Blue round will be 720/4 = 180.

Hope this information will clear your doubts about the Lathyrus odoratus.
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