Assertion (A) : Performance of synthetic varieties are better than single or double cross hybrids
Reason (R) : Synthetics exploit only general combining ability (GCA) while hybrids exploit GCA and specific combining ability (SCA).
In the light of the above statements, choose the most appropriate answer from the options given below :
Analysis of Statements on Crop Varieties
Assertion (A) Analysis: Performance of Synthetic Varieties
The assertion states that the performance of synthetic varieties is better than single or double cross hybrids. This statement is generally considered incorrect in plant breeding.
- Synthetic varieties are developed from multiple parent lines selected for their general combining ability (GCA).
- Double cross hybrids, in particular, are known to exhibit higher performance due to the exploitation of both general combining ability (GCA) and specific combining ability (SCA), leading to greater heterosis.
- Therefore, double cross hybrids typically outperform synthetic varieties.
Reason (R) Analysis: Combining Ability Exploitation
The reason states that synthetics exploit only general combining ability (GCA) while hybrids exploit GCA and specific combining ability (SCA). This statement is correct.
- Synthetics: Their development primarily focuses on improving the average performance of the population by selecting parents with good GCA.
- Hybrids (Single and Double Cross): These are specifically bred to capitalize on the superior performance resulting from the unique combination of parents, which involves exploiting both GCA and, crucially, specific combining ability (SCA). Double crosses further enhance this by combining two superior single crosses.
Conclusion
Based on the analysis:
- Assertion (A) is incorrect because synthetic varieties generally do not outperform advanced hybrids like double crosses.
- Reason (R) is correct as it accurately describes the genetic basis (GCA vs. GCA and SCA) for the performance of synthetics and hybrids.
Since (A) is incorrect and (R) is correct, the most appropriate choice is that (A) is not correct but (R) is correct.
Similar Questions
- Zero tillage is a method of conservation tillage. Which of the following statements are true abut it :
A. Zero tillage is an extreme form of minimum tillage.
B. In Zero tillage, herbicide functions are extended
C. It is an energy consuming operation
D. It promotes the rapid decomposition of soil organic matter
E. In Zero tillage, primary tillage is completely avoided and secondary tillage is restricted to root zone only.
Choose the correct answer from the options given below : - Select the correct statements about the Igneous rocks.
A. Igneous rocks are formed from the consolidation of sediments
B. Igneous rocks are formed by solidification of molten material magma on or beneath benefits of earth surface
C. Igneous rock make up 95% of the earth crust
D. Gneiss and slate are the example of igneous rocks
E. Granite and sandstone are the example of igneous rocks
Choose the correct answer from the options given below : - The correct sequence of soil development stages is :
A. Initial stage
B. Virile stage
C. Senile stage
D. Juvenile stage
E. Final stage
Choose the correct answer from the options given below : - Arrange the following liming materials, in increasing order as per their neutralizing value of calcium carbonate equivalent (CCE) % :
A. Calcium oxide
B. Calcium hydroxide
C. Dolomite
D. Calcite
E. Basic Slag
Choose the correct answer from the options given below : - Decreasing order of elements as per their average composition in earth crust (% by weight) is :
A. Al3+
B. Fe2+
C. Si4+
D. Ca2+
E. Na+
Choose the correct answer from the options given below : - Increasing order of fertilizers as per their salt index is :
A. Urea
B. Sodium nitrate
C. Ammonium sulphate
D. Ammonium nitrate
E. Potassium nitrate
Choose the correct answer from the options given below : - Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Specific crop intensity index (SCII) is a derivative of cropping intensity index (CII)
Reason (R) : SCII determines the amount of area time devoted to each crop compared to the total time available to the farmer
In the light of the above statements, choose the most appropriate answer from the options given below : - Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : The first tractor was developed in the USA in 1910.
Reason (R) : The DDT and BHC insecticides were discovered in 1939.
In the light of the above statements, choose the most appropriate answer from the options given below : - Given below are two statements : one is labelled as Assertion (A) and the other is labelled as Reason (R).
Assertion (A) : Nitrogen is usually lost from applied ammonium and amide containing fertilizers after their conversion to nitrate form.
Reason (R) : Application of N-Serve (2-chloro-6-trichloromethyl pyridine) and AM (2-amino-4-chloro-6 methyl-pyrimidine) can reduce these losses and increase the efficiency of applied nitrogen fertilizers.
In the light of the above statements, choose the most appropriate answer from the options given below : - Which one of the following is not a principles of organic farming :
Important Questions from Mixed Topic (CUET PG)
- Who was the founder of Bolshevik Communist party?
- What is the key guide to statecraft in the realist tradition?
- Chronologically arrange the events in the Cold War period.
A. Berlin Wall is constructed
B. Communist China joins the UN
C. Soviet invasion of Czechoslovakia
D. Berlin Blockade
Choose the correct answer from the options given below: Morgenthau's principles of political realism are:
A. Politics is rooted in permanent and unchanging human nature which is basically self centred, self-regarding and self-interested
B. Politics is an autonomous sphere of action and cannot therefore be reduced to morals
C. International Politics is an arena of conflicting self-interests
D. The ethics of international relations is situational ethics which is very different from private morality
Choose the correct answer from the options given below:Who among the following political thinkers consider the anarchical self help system to be a compelling factor for States to maximise their relative power positions?
